JP5334654B2 - Cushion pad mold and cushion pad manufacturing method using the mold - Google Patents

Description

  The present invention relates to a molding die for molding a cushion pad made of foamed resin used for, for example, an automobile seat and the like, and a cushion pad manufacturing method using the molding die.

  A seat such as a vehicle represented by an automobile mainly includes a backrest portion and a cushion pad for a seating portion. For example, the cushion pad of the backrest portion is formed with an extending portion extending from the upper edge to the back side, and the upper portion of the cushion pad has a U-shaped cross section. As a manufacturing method for forming a cushion pad having this extended portion, Patent Document 1 discloses a method for manufacturing a seat pad.

  Patent Document 1 discloses a lower mold that is formed from the back surface of the pad body of the cushion pad to the outer surface of the upper edge portion of the cushion pad extending portion (extension portion), and a lower portion of the extending portion below the upper edge portion. A manufacturing method is disclosed that uses a three-part mold that includes an upper mold that forms an outer surface, and a core mold that forms the back surface of the pad main body, the inner surface of the extending portion, and the tip surface.

  However, in the manufacturing method using this three-part mold, in the extended portion, when the thickness of the tip portion is set to be thinner than the thickness of the other portion, the reduced thickness portion In this case, the flow of the foamed resin raw material liquid becomes worse, and molding defects (voids) may occur. Furthermore, when this reduced thickness portion is formed on the upper side (higher position) than the parting line (mating surface) between the upper mold and the middle mold, the gas escape is bad and the gas tends to accumulate. As a result, molding defects may occur.

  Therefore, in Patent Document 1, in order to improve the above-described molding failure, the foamed resin raw material liquid is bypassed as an insert material in the core-shaped part in the reduced thickness portion where the flow of the foamed resin raw material liquid becomes poor. A manufacturing method is disclosed in which a member is fixed to improve the liquid flow of the foamed resin raw material liquid at the time of forming a cushion pad and to prevent generation of voids.

  However, the cushion pad manufactured by the manufacturing method disclosed in Patent Document 1 is manufactured because the foamed resin raw material liquid bypass member that is an insert material is provided as part of the cushion pad while being embedded in the cushion pad. An insert material is used for each cushion pad to be used, resulting in an increase in manufacturing cost of the cushion pad.

  On the other hand, as a technique for solving the problem of using an insert material for each cushion pad to be manufactured, Patent Document 2 describes a portion in which the flow of the foamed resin raw material liquid is poor in a three-part mold. A cushion pad manufacturing method using a molding die in which a convex portion is formed on a core die is disclosed.

  When a cushion pad is molded using the molding die disclosed in Patent Document 2, since the convex portion provided in the core mold is in an intricate part inside the extended portion, the molded cushion pad is removed. Undercut shape with respect to the direction, and the molded cushion pad is made of foamed resin and has elasticity, so that when the mold is removed from the core mold, the extension part is elastically deformed so that the mold can be removed. There was a problem that the workability of was not good.

  Furthermore, in Patent Document 3, when a reinforcing cloth material is present in a portion where the flow of the foamed resin raw material liquid becomes poor when the cushion pad is molded, a rectifying fin is formed in a part thereof, and the reinforcing cloth material In the case where there is not, there is disclosed a method of manufacturing a cushion pad in which a current plate is projected in the mold and the original flow of the foamed resin raw material liquid is prevented by the current plate and directed to a portion where the liquid flow is bad.

  However, in the manufacturing method disclosed in Patent Document 3, since the flow of the foamed resin raw material liquid is only hindered by the rectifying fins and rectifying plates, it is not sufficient to improve the liquid flow and prevent the generation of voids. There wasn't.

JP 2007-82909 A JP 2008-183129 A JP 2008-125695 A

  The present invention has been made in view of the above problems, and an extended portion extending from the upper edge of the foamed cushion pad to the back side so that the upper portion of the cushion pad has a U-shaped cross section is formed at the tip thereof. Since it has a thin part and the thickness of the extended part decreases sharply, the extended part is in the middle of molding the cushion pad in order to sufficiently improve the molding defect that a void occurs in the front part of this thin part. Cushion pad that prevents the generation of voids due to the presence of a recess inside the thick wall portion on the upper edge side, and improves the workability during die cutting by eliminating the recess inside the thick wall portion when molding is completed It is an object of the present invention to provide a mold and a method for manufacturing a cushion pad using the mold.

  In order to solve the above problem, the present inventors have a cushion in which a recess is present inside the thick portion of the extending portion during molding of the cushion pad, and the recess inside the thick portion disappears when molding is completed. The pad mold was studied earnestly. As a result, the reinforcing cloth material is pressed against the surface of the core mold portion corresponding to the inside of the thick wall portion of the cushion pad to be molded by elastic force from the surface of the core mold, and the reinforcing cloth is pressed into the thick wall portion. Void generation without increasing the cost of manufacturing the cushion pad by providing an elastic pressing part that bulges the material and retreats when the foamed resin is filled into the thick-walled part. It has been found that a foamed resin cushion pad can be obtained which sufficiently improves the molding defects due to the above and further improves the workability in the mold removal because no concave portion remains inside the thick wall portion.

The present invention has been made on the basis of the above-described knowledge, and the gist of the present invention is as follows.
(1) An extending portion that extends from the upper edge portion of the cushion pad made of foamed resin to the back side and has a U-shaped cross section at the upper portion of the cushion pad, and a connecting portion that extends backward from the upper edge portion; The foamed resin and the reinforcing cloth material covering the foamed resin are integrally formed at least inside the thick part, having a thick part connected to the connecting part and a thin part on the distal end side of the extended part. A mold for molding the cushion pad,
A lower mold for forming the shape of the front side of the cushion pad;
A core mold for forming the shape of the back surface side of the cushion pad and the shape of the inside of the extended portion;
An upper mold for forming a shape on the back surface side including the outside of the extended portion of the cushion pad;
With
The core mold protrudes from the surface of the core mold by an elastic force, presses the reinforcing cloth material, causes the reinforcing cloth material to bulge into the thick wall portion, and the foamed resin enters the thick wall portion. A cushion pad mold having an elastic pressing part which is pressed by the reinforcing cloth material and retracts when filled.
(2) The cushion pad molding according to the above (1), wherein the elastic pressing portion bulges the reinforcing cloth material to make the thickness of the thick portion smoothly connect to the connecting portion. Type.
(3) The above-mentioned (1) or the above, wherein the elastic pressing part is retracted along the surface of the core mold when a filling pressure of 75% to 95% of the maximum filling pressure of the foamed resin is applied. (2) The cushion pad mold according to the description.
(4) When the width of the extending portion in a direction orthogonal to the extending direction of the extending portion is L, the width of the elastic pressing portion is at least 0.8 L, and the elastic pressing portion The cushion pad mold according to any one of (1) to (3) above, wherein a distance between each of both end portions in the width direction of the A and the outer surface of the extending portion is 15 mm or more.
(5) The cushion pad mold according to any one of (1) to (4), wherein the cushion pad is a back pad for an automobile seat.
(6) An extending portion that extends from the upper edge portion of the cushion pad made of foamed resin to the back side and has an upper portion of the cushion pad that is U-shaped in cross section, and a connecting portion that extends rearward from the upper edge portion; The foamed resin and the reinforcing cloth material covering the foamed resin are integrally formed at least inside the thick part, having a thick part connected to the connecting part and a thin part on the distal end side of the extended part. A method of manufacturing the cushion pad, comprising:
A lower mold for forming a shape on the front side of the cushion pad; a core mold for forming a shape on the back surface side of the cushion pad and an inner side of the extending portion; and the extension of the cushion pad. An upper mold for forming a shape on the back side including the outside of the installation part
The core mold protrudes from the surface of the core mold by an elastic force, presses the reinforcing cloth material, causes the reinforcing cloth material to bulge into the thick wall portion, and the foamed resin enters the thick wall portion. Using a cushion pad mold that has an elastic pressing part that is pushed back by the reinforcing cloth material when filled,
When molding the cushion pad with the mold,
The reinforcing cloth material is disposed on at least the surface corresponding to the thick wall portion of the core-shaped surface provided with the elastic pressing portion,
In a state where the reinforcing cloth material is pressed by the elastic pressing portion and bulged from the surface of the core mold, a foamed resin raw material liquid is injected into the mold,
The foamed resin raw material liquid is foamed and filled in the mold, and the elastic pressing part is pressed and retreated with the reinforcing cloth material by the filling pressure in the thick part,
A method of manufacturing a cushion pad, comprising curing the filled foam resin material liquid.

  In the cushion pad mold according to the present invention, the core mold is protruded from the surface of the core mold by an elastic force to press the reinforcing cloth material, and the reinforcing cloth material is swelled into the thick wall portion and foamed. When the resin is filled in the thick wall part, there is an elastic pressing part that is pressed by the reinforcing cloth material and retreats, so the foamed resin raw material liquid is foamed in the mold and the foamed resin raw material liquid is put in the mold When filling, the reinforcing cloth material pressed by the elastic pressing part and bulging into the thick part forms a recess in the thick part, and the flow of the foamed resin raw material liquid flowing into the thick part from the connecting part is The flow is rectified at the concave portion and led to the thin wall portion at the distal end side of the extended portion to promote gas escape and prevent the occurrence of molding defects (voids). Then, after the foamed resin is filled in the thick wall portion in the state where the concave portion exists, the elastic pressing portion is pushed back by the reinforcing cloth material subjected to the filling pressure (expansion pressure) of the foamed resin, and the concave portion exists. Since the foamed resin fills the space that has been formed, the concave portion formed by the reinforcing cloth material inside the thick portion at the start of molding the cushion pad does not exist when the cushion pad molding is completed.

  Therefore, according to the cushion pad molding die of the present invention, the molding failure of the cushion pad is sufficiently improved by the elastic pressing portion without causing an increase in the manufacturing cost of the cushion pad using the insert material remaining in the cushion pad. Moreover, since the elastic pressing part is pressed by the foamed resin and retreats, there is no concave part inside the thick-walled part, so that it is possible to obtain a foamed resin cushion pad that improves workability at the time of mold release. .

  In the cushion pad mold according to the present invention, the elastic pressing portion bulges the reinforcing cloth material so that the thickness of the thick portion is smoothly connected to the connecting portion. Effectively rectifies the flow of the foamed resin raw material liquid and promotes gas escape, which is more preferable for sufficiently improving molding defects.

  Further, in the cushion pad mold of the present invention, the elastic pressing part moves backward along the surface of the core mold when a filling pressure of 75% or more and 95% or less of the maximum filling pressure of the foamed resin is applied. If there is, the cushion pad can be filled with the foamed resin just before the molding of the foamed resin in the mold is completed, by retracting the elastic pressing part along the surface of the core mold. The recess formed by the reinforcing cloth material on the inside of the thick portion at the start of molding is more preferable because it can be completely eliminated when the cushion pad is completely molded. Note that if the pressure is less than 75% of the maximum filling pressure, the elastic pressing portion is retracted during the flow of the foamed resin, and if it exceeds 95%, the filling of the foamed resin is almost completed and the elastic pressing portion is retracted. Even so, it is not preferable because the space where the recesses existed cannot be filled with the foamed resin. By the way, the maximum filling pressure of the foamed resin in the mold is usually 30 kPa or more and 120 kPa or less. For example, when the maximum filling pressure is 30 kPa, the elastic pressing part is set so as to be completely retracted when the filling pressure becomes 25 kPa, for example. It is preferable to set.

  Furthermore, in the cushion pad molding die of the present invention, when the width of the extending part of the cushion pad in the direction orthogonal to the extending direction of the extending part is L, the width of the elastic pressing part is at least 0. 0. It is preferable that the distance l between each of both ends in the width direction of the elastic pressing portion and the outer surface of the extending portion is 15 mm or more. This is because when the width of the elastic pressing portion is less than 0.8 L, the bulging portion of the reinforcing cloth material having a liquid flow bypass function is included in the thick portion with respect to the liquid flow of the foamed resin raw material liquid when molding the cushion pad. When the distance l is less than 15 mm, the foamed resin raw material liquid flows to both sides of the extended portion when the cushion pad is molded. This is because it becomes worse and the effect of preventing molding defects in the vicinity of both sides of the extended portion decreases.

  The cushion pad mold according to the present invention can form a cushion pad having an extending portion extending from the upper edge portion to the back side and having an upper portion of the cushion pad having a U-shaped cross section. It can be suitably used when molding.

  Further, according to the cushion pad manufacturing method of the present invention, the reinforcing cloth material is protruded from the surface of the core mold by the elastic force to press the reinforcing cloth material, and the reinforcing cloth material is bulged into the thick wall portion. When the foamed resin is filled in the thick part, an elastic pressing part provided with an elastic pressing part that is pressed and retreated by the reinforcing cloth material is used. A state in which the reinforcing cloth material is disposed on at least the surface corresponding to the thick wall portion of the provided core surface, and the reinforcing cloth material is pressed by the elastic pressing portion to bulge from the core surface. Then, the foamed resin raw material liquid is injected into the mold, the foamed resin raw material liquid is foamed and filled in the mold, and the elastic pressing part is pressed with the reinforcing cloth material by the filling pressure in the thick part. Since the foamed resin raw material liquid that is filled is cured When the foamed resin raw material liquid is foamed in the mold and filled with the foamed resin raw material liquid, the reinforcing cloth material swelled into the thick part by being pressed by the elastic pressing part is placed in the thick part. A recess is formed, and the flow of the foam resin raw material flow that flows into the thick part from the connecting part is rectified by the recess to guide it to the thin part on the distal end of the extension part, which leads to outgassing and the occurrence of molding defects (voids). To prevent. Then, after the foamed resin is filled in the thick wall portion in the state where the concave portion exists, the elastic pressing portion is pushed back by the reinforcing cloth material subjected to the filling pressure (expansion pressure) of the foamed resin, and the concave portion exists. Since the foamed resin fills the space that has been formed, the concave portion formed by the reinforcing cloth material inside the thick portion at the start of molding the cushion pad does not exist when the cushion pad molding is completed.

  Therefore, according to the cushion pad manufacturing method of the present invention, the molding failure of the cushion pad is sufficiently improved by the elastic pressing portion without causing an increase in the manufacturing cost of the cushion pad using the insert material remaining in the cushion pad. In addition, since the elastic pressing portion is pressed by the foamed resin and retreats, the concave portion does not remain inside the thick-walled portion, so that it is possible to obtain a foamed resin cushion pad that improves the workability at the time of mold removal it can.

It is a perspective view which shows the cushion pad shape | molded with the cushion pad shaping | molding die of one Embodiment of this invention. It is sectional drawing which follows the II line | wire in FIG. It is a schematic diagram which shows the longitudinal cross-section of the said cushion pad shaping | molding die. It is explanatory drawing which expands and shows an example of the elastic press part provided in the said cushion pad shaping | molding die. It is explanatory drawing which expands and shows another example of the elastic press part provided in the said cushion pad shaping | molding die. It is explanatory drawing which expands and shows another example of the elastic press part provided in the said cushion pad shaping | molding die. It is a characteristic line figure which shows the change condition of the internal pressure by foaming of the foaming resin raw material liquid in the said cushion pad shaping | molding die. It is explanatory drawing which shows the condition in the cavity near the thick part during foam molding of the said cushion pad shaping | molding die. It is explanatory drawing which shows the state which the bubble stayed in the thick part part, when a cushion pad is shape | molded without providing an elastic press part in the core type | mold of a cushion pad shaping | molding die.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing a cushion pad formed by a cushion pad mold according to an embodiment of the present invention, and FIG. 2 is a longitudinal sectional view taken along line II in FIG. In FIG. 1, the code | symbol 1 shows the said cushion pad. The cushion pad 1 is an automobile seat back pad. Reference numeral 2 denotes the front side of the cushion pad 1, reference numeral 3 denotes the back side of the cushion pad 1, and reference numeral 4 denotes the upper edge of the cushion pad 1.

  Reference numeral 5 denotes an extending portion extending from the upper edge portion 4 to the back side 3 of the cushion pad 1 so that the upper portion of the cushion pad has a U-shaped cross section. Reference numeral 5a denotes an outside of the extending portion, and reference numeral 5b denotes an extending portion. The inside of the installation portion, reference numeral 5c is the extended portion tip. The extending portion 5 includes a connecting portion 6 on the upper edge 4 side and a thick portion 7 connected thereto, and a thin portion 8 on the extending portion distal end 5c side. The elastic pressing portion 15 described later included in the cushion pad mold according to the above embodiment is disposed at the position of the thick portion 7 on the extending portion inner side 5c, as indicated by a virtual line in FIG. The cushion pad 1 has a reinforcing cloth material 10 formed integrally with the pad main body 9 made of foamed resin and covering the pad main body 9 on the back side 3 and the back surface of the extending portion inner side 5c.

  The thin-walled portion 8 serves as a seating surface to which a resin plate called a backboard that improves the appearance of the back side 3 of the cushion pad 1 is attached. In the extended portion 5, the wall thickness rapidly decreases while moving from the thick portion 7 to the thin portion 8. Due to this sudden decrease in thickness, the flow of the foamed resin raw material liquid becomes poor as it is, and causes molding defects such as voids in the thick portion 7. Therefore, in order to improve such a poor flow of the foamed resin raw material liquid, the cushion pad mold of the above embodiment has a recess in the extended portion inner side 5b of the thick portion 7 during the molding of the cushion pad 1. Thus, the poor flow of the foamed resin raw material liquid is improved, and molding defects such as voids in the thick portion 7 are prevented. When the molding is completed, the recessed portion of the extended portion inner side 5b of the thick portion 7 is eliminated, so that the workability at the time of removing the molded cushion pad 1 is improved.

  FIG. 3 is a schematic view showing a longitudinal section of the cushion pad mold of the above embodiment. In FIG. 3, reference numeral 11 denotes the cushion pad mold of the above embodiment. FIG. 3 also shows a reinforcing cloth material 10 that is disposed in the cushion pad mold 11 when the pad main body 9 is foam-molded.

  The cushion pad mold 11 is a three-part mold, and includes an upper mold 12, a core mold 13, and a lower mold 14. In FIG. 3, the phantom lines indicate a state where the core mold 13 is opened together with the upper mold 12. The lower mold 14 forms the shape of the front side 2 of the cushion pad 1. The core mold 13 forms the shape of the back side 3 of the cushion pad 1 and the shape of the extending portion inner side 5b. The upper mold 12 forms the shape of the back side 3 including the shape of the extending portion outer side 5 a of the cushion pad 1.

  The upper mold 12 is provided with a step forming portion 12a that forms the shape of the extending portion outer side 5a extending from the thick portion 7 to the thin portion 8 of the cushion pad 1, whereby the extending portion of the cushion pad 1 is provided. The cross-sectional thickness of 5 rapidly decreases from the thick portion 7 toward the thin portion 8.

  The parting line PL between the upper mold 12 and the core mold 13 is necessary when the foamed resin raw material liquid injected into the cushion pad mold 11 foams and fills the cushion pad mold 11. It functions as a gas escape passage. When the step forming portion 12a is provided in front of the parting line PL (upstream side in the direction of the flow of the foamed resin raw material liquid) and at a position higher than the parting line PL, the step forming portion 12a remains on the wall as it is. As a result, outgassing is inhibited and the liquid flow of the foamed resin raw material liquid is deteriorated, resulting in defective molding such as generation of voids. Therefore, in the cushion pad mold 11 of this embodiment, in order to improve the gas flow from the step forming portion 12a and the flow of the foamed resin raw material liquid in the step forming portion 12a, An elastic pressing portion 15 is provided at a position where the thick portion 7 of the cushion pad 1 is formed.

  The elastic pressing portion 15 protrudes from the surface of the core mold 13 with an elastic force to press the reinforcing cloth material 10 to bulge the reinforcing cloth material 10 into the thick-walled portion 7, so that it is thick during molding of the foamed resin. A concave portion is formed in the meat portion 7, and when the foamed resin is filled in the thick portion 7, it is pressed by the reinforcing cloth material 10 to move backward, and the concave portion disappears. 4 to 6 can be configured.

  Here, the elastic pressing portion 15 shown in FIG. 4 is a magnet in which one side (lower side in the figure) of the spring steel plate 15a bent in a V-shaped cross section is embedded in, for example, an adhesive tape or a core mold 13 or the like. And fixed to a position 13a of the surface of the core mold 13 where the thick part 7 of the cushion pad 1 is formed, and the other side opened with respect to the one side by the elasticity of the bent part between the two sides (in the figure The reinforced fabric material 10 is pressed by the upper side) to form the bulged portion 10a of the reinforced fabric material 10, thereby forming the foamed resin at the bulged portion 10a of the reinforced fabric material 10. When a concave portion is formed in the thick wall portion 7 and a predetermined filling pressure is applied from the foamed resin to the bulging portion 10a of the reinforcing cloth material 10, the other side is pressed by the reinforcing cloth material 10 and an imaginary line in FIG. Retreat as shown by and substantially eliminate the recess.

  The elastic pressing portion 15 shown in FIG. 5 supports the pressing plate 15b with a coil spring 15c, and the base portion (lower end portion in the figure) of the coil spring 15c is the thick wall of the cushion pad 1 on the surface of the core mold 13. The guide pin 15e, which is fixed in the groove portion 15d formed at the position 13a where the portion 7 is formed and is provided in the pressing plate 15b, is guided through the guide hole 15f formed in the groove portion 15d, and the elasticity of the coil spring 15c. Thus, the reinforcing cloth material 10 is pressed through the pressing plate 15b to form the bulging portion 10a of the reinforcing cloth material 10, so that the bulging portion 10a of the reinforcing cloth material 10 can be expanded with foam resin. When a concave portion is formed in the thick portion 7 during molding, and a predetermined filling pressure is applied from the foamed resin to the bulging portion 10a of the reinforcing cloth material 10, the pressing plate 15b is pressed by the reinforcing cloth material 10 and the coil spring 15c. In the figure while compressing Retracted into the groove portion 15d as shown by line, to flatten the surface of the core die 13, to eliminate the recess. In the groove portion 15d, part or all of the air and gas trapped on the core mold 13 side of the bulging portion 10a can be released when the pressing plate 15b is retracted. If the guide hole 15f communicates with the outside of the core mold 13, air or gas can be released through the guide hole 15f.

  The elastic pressing portion 15 shown in FIG. 6 has two lid plates 15g hinged to the entrance of a groove portion 15d formed at a position 13a on the surface of the core mold 13 where the thick portion 7 of the cushion pad 1 is formed. The elastic body 15h such as a urethane tip is fixed in the groove portion 15d so as to be swingable with each other, and a reinforcing cloth is provided via the two cover plates 15g by the elasticity of the elastic body 15h. The material 10 is pressed to form the bulging portion 10a of the reinforcing cloth material 10, and the bulging portion 10a of the reinforcing cloth material 10 thereby forms the thick portion 7 during molding of the foamed resin. When a predetermined filling pressure is applied from the foamed resin to the bulging portion 10a of the reinforcing cloth material 10 by forming a recess, the two cover plates 15g are pressed by the reinforcing cloth material 10 to compress the elastic body 15h in the figure. Into the groove 15d as shown by the phantom line Withdrawal to, and flattening the surface of the core die 13, to eliminate the recess. In the groove portion 15d, part or all of the air and gas trapped on the core mold 13 side of the bulging portion 10a can be released when the two lid plates 15g are retracted.

  FIG. 7 exemplifies a change state of the internal pressure due to foaming of the foamed resin raw material liquid in the cushion pad mold 11, and the maximum filling pressure of the foamed resin in the mold is usually 30 kPa or more and 120 kPa or less. In this illustrated example, the internal pressure suddenly rises from about 50 seconds after the foamed resin raw material liquid is discharged into the cushion pad mold 11, and the maximum foaming internal pressure (maximum filling pressure) is reached after about 100 seconds. After reaching 0.03 MPa (30 kPa), it slowly descends. Since the filling of the foamed resin raw material liquid in the cushion pad mold 11 has been completed when the maximum foaming internal pressure is reached, the foaming internal pressure (predetermined filling pressure) when the elastic pressing portion 15 is completely retracted is: Set a little lower than the maximum foaming pressure. For example, when the maximum filling pressure is 0.03 MPa (30 kPa) as in this example, the cushion pad mold 11 of this embodiment has a filling pressure of 0.025 MPa (25 kPa), that is, 83% of the maximum filling pressure. It is preferable to set the elastic force of the elastic pressing portion 15 so that the elastic pressing portion 15 is completely retracted.

  By the way, the surface of the extended portion inner side 5b of the molded cushion pad 1 is formed so as to have the reinforcing cloth material 10 integrally. The core described in Patent Document 2 is provided on the extended portion inner side 5b. When forming a concave portion with a metal convex portion like a mold, the concave portion of the reinforcing cloth material is the core type when the molded cushion pad is removed even if a sufficient escape gradient is given to the concave portion. The workability is not good due to being caught by the convex part. This is because when the foamed resin raw material liquid injected into the cavity of the mold is foamed and hardened when the cushion pad is molded, a pressure of 30 to 120 kPa is applied to the inner surface of the mold, and after the foamed resin raw material liquid is cured This is because the metal convex portion of the core mold is tightened with the cured foamed resin, and the reinforcing cloth material 10 is easily caught.

  On the other hand, the elastic pressing portion 15 in this embodiment is pushed back by the reinforcing cloth material 10 when a predetermined filling pressure is applied from the foamed resin to the bulging portion 10a of the reinforcing cloth material 10 immediately before the molding of the foamed resin is finished. Then, the concave portion formed by the bulging portion 10a is substantially eliminated. For this reason, when the molded cushion pad 1 is removed, the reinforcing cloth material 10 is not caught by the core mold, so that the workability of the removal work is improved.

  The reinforcing cloth material 10 is mainly used for reinforcing and protecting the cushion pad 1 and suppressing the generation of a rubbing sound with the seat frame. Examples of the material include felt, non-woven fabric, and cloth. From the viewpoint of thermoforming, felt or non-woven fabric is preferable, and felt is particularly preferable. The thickness or basis weight of the reinforcing cloth material 10 can be appropriately set according to the specification of the cushion pad. Further, although it is a range in which the reinforcing cloth material 10 is molded integrally with the foamed resin, at least on the inner surface of the thick portion 7 in order to prevent the foamed resin from adhering to the elastic pressing portion 15 at the time of foam molding, The foamed resin and the reinforcing cloth material 10 need to be integrally formed. The reinforcing cloth material 10 is preferably made of a flexible material that can be three-dimensionally formed along the shape of the back surface side of the cushion pad 1 and the surface shape of the core mold 13 and can form the bulging portion 10a. The reinforcing cloth material 10 is preferably preliminarily thermoformed so as to conform to the shape of the back surface side of the cushion pad 1 and the surface shape of the core mold 13.

  The reinforcing cloth material 10 used in the present embodiment is made of felt, and is thermoformed in advance so as to follow the shape of the back surface side of the cushion pad 1 and the inside of the extending portion 5. The felt thermoforming method is not particularly limited.

  Next, the dimension of the elastic pressing part 15 is demonstrated. As indicated by phantom lines in FIG. 1, the elastic pressing portion 15 has a longitudinal direction in a direction orthogonal to the extending direction of the extending portion 5 (a direction orthogonal to the paper surface in FIG. 3). Therefore, the dimension of the elastic pressing portion 15 in the longitudinal direction is the width of the elastic pressing portion 15. The elastic pressing part 15 is provided in the core mold 13 in order to improve the liquid flow of the foamed resin raw material liquid when the cushion pad 1 is molded. The width of the part 15 is particularly important. When the width of the extending portion 5 of the cushion pad 1 to be molded is L as shown in the drawing in the direction perpendicular to the extending direction of the extending portion 5, the width of the elastic pressing portion 15 is at least 0. 0. It is preferable that the distance l between each of both end portions in the width direction of the elastic pressing portion 15 and the outer surface of the extending portion 5 of the cushion pad 1 to be molded is 15 mm or more. This is because, when the width of the elastic pressing portion 15 is less than 0.8 L, the bulging portion 10a of the reinforcing cloth material 10 having a liquid flow detouring function with respect to the liquid flow of the foamed resin raw material liquid when the cushion pad 1 is molded. When the distance l is less than 15 mm, the extending portion 5 of the foamed resin raw material liquid for molding the cushion pad 1 is reduced. This is because the liquid flow to both side portions of the extension portion deteriorates and the effect of preventing molding defects in the vicinity of both side portions of the extended portion 5 is reduced. In the present embodiment, the width of the elastic pressing portion 15 is 0.8L.

  Next, a method for manufacturing the cushion pad 1 using the cushion pad mold 11 will be described.

  First, as indicated by a virtual line in FIG. 3, the core mold 13 is opened together with the upper mold 12, and the reinforcing cloth material 10 is fixed to a predetermined position of the core mold 13 provided with the elastic pressing portion 15. Thereby, as shown in FIG. 3, the portion of the reinforcing cloth material 10 facing the elastic pressing portion 15 is pressed by the elastic pressing portion 15 to bulge out, and the bulging portion 10 a of the reinforcing cloth material 10 becomes the cushion pad. It is formed in the mold 11.

  Next, in the state where the core mold 13 is opened together with the upper mold 12 as described above, a predetermined amount of a foamed resin raw material liquid of, for example, a flexible polyurethane foam is injected into the lower mold 14.

  Then, the upper mold 12 and the core mold 13 are closed on the lower mold 14 to form a cavity in the cushion pad mold 11, and the cushion pad mold 11 is heated at a predetermined temperature for a predetermined time. Thus, foaming of the foamed resin is performed. FIG. 8 is an explanatory diagram showing a situation in the cavity near the thick portion 7 during foam molding.

  The foamed resin raw material liquid 16 in the lower mold 14 is foamed to increase the volume, and flows between the upper mold 12 and the core mold 13. That is, the foamed resin raw material liquid 16 in the lower mold 14 forms the thick part 7 through the molding surface 12b of the upper mold 12 that forms the thick part 7 and the reinforcing cloth material 10 of the core mold 13. The bulging portion 10a of the reinforcing cloth material 10 smoothly flows into the portion corresponding to the thick portion 7 of the cavity to the portion corresponding to the connecting portion 6 in front of the molding surface 13a. Therefore, the flow direction of the foamed resin raw material liquid 16 can be smoothly changed by the bulging portion 10a of the reinforcing cloth material 10, and as shown by arrow A in FIG. It flows along the molding surface 12b of the upper mold 12 on the concave portion formed inside the thick portion 7 of the extending portion 5 by the bulging portion 10a of the reinforcing cloth material 10. Thereby, the air and foaming gas mixed in the foamed resin raw material liquid 16 form the thin-walled portion 8 of the core mold 13 together with the foamed resin raw material liquid 16 without staying as bubbles in the step forming portion 12a. It reaches the tip of the molding surface 13b.

  Furthermore, the air that has passed through the portion corresponding to the thick portion 7 of the cushion pad 1 in the cushion pad mold 11 is parted between the upper die 12 and the core die 13 located downstream of the step forming portion 12a. The line PL exits as shown by the arrow B in FIG. Since the parting line PL is located at the corner of the portion corresponding to the thin portion 8, air or gas is exhausted without remaining between the upper mold 12 and the core mold 13, and the upper mold 12 and the middle The foamed resin raw material liquid 16 can be filled evenly between the child molds 13. FIG. 9 shows a state where the bubbles 17 stay in the step forming portion 12a in the cushion pad mold 11 when the cushion pad is molded without providing the bulging portion 10a of the reinforcing cloth material 10.

  Thereafter, when the filling of the foamed resin raw material liquid 16 between the upper mold 12 and the core mold 13 proceeds, the filling pressure of the foamed resin raw material liquid 16 in the cushion pad mold 11 increases as shown in FIG. The reinforcing cloth material 10 starts to push back the elastic pressing portion 15 by the filling pressure. When the filling pressure of the foamed resin raw material liquid 16 reaches the above-described predetermined filling pressure, the elastic pressing portion 15 is pushed back to a position substantially flush with the surface of the core mold 13, and the bulging portion 10 a of the reinforcing cloth material 10. The space occupied by is filled with the expanded foamed resin raw material liquid 16, and the concave portion formed inside the thick portion 7 of the extended portion 5 disappears.

  After the cushion pad 1 is molded in this manner, the mold 11 is cooled as necessary, the upper mold 12 is rotated upward to open the mold, and the core that holds the molded cushion pad 1 is held. The mold 13 is separated from the upper mold 12, and then the cushion pad 1 molded from the core mold 13 is removed. Here, the pad main body 9 made of the foamed resin after the foam molding has been removed from the reinforcing member 10 to form the cushion pad 1, but the elastic pressing portion 15 is left on the surface of the core mold 13. Will remain. Therefore, when the cushion pad 1 is subsequently formed, only the reinforcing cloth material 10 may be disposed on the core mold 13 provided with the elastic pressing portion 15.

  The invention is further illustrated in the following examples.

Using the cushion pad mold 11 of the above embodiment shown in FIG. 3, a sample of the cushion pad 1 was molded as follows. In addition, the width L (refer FIG. 1) of the extension part 5 of the cushion pad 1 in the direction orthogonal to the extension direction of the extension part 5 was 190 mm.
(Sample No. 1-9)
4 to 6 are provided in the cushion pad mold 11 and sample Nos. 1 to 9 are used as sample Nos. 1 to 9. 1-No. Ten pieces of 9 were formed. Sample No. The width of the elastic pressing portion 15 in 1 to 9 was 0.8 L, and the ratio of the filling pressure when the elastic pressing portion 15 was completely retracted to the maximum filling pressure was changed as shown in Table 1 described later (however, The maximum filling pressure was 0.03 MPa (30 kPa)).
(Sample No. 10)
As Comparative Example 1, the sample No. was changed except that the ratio of the filling pressure when the elastic pressing portion 15 was completely retracted to the maximum filling pressure was 100%. Sample No. 2 under the same conditions. Ten 10 pieces were molded.
(Sample No. 11)
As Comparative Example 2, the sample No. was changed except that the ratio of the filling pressure when the elastic pressing portion 15 was completely retracted to the maximum filling pressure was 70%. Sample No. 2 under the same conditions. Ten 11 were molded.

The void generation rate of each sample thus obtained and the workability during die cutting were evaluated in the following manner.
(Void occurrence rate)
Sample No. The occurrence of voids at the end of the thick portion 7 was investigated for 10 pieces each of 1 to 11, and the void generation rate was calculated and evaluated as follows.
A: Void occurrence rate 0%
○: Void occurrence rate of 10% or less (excluding 0%)
×: Void generation rate exceeds 10% (die cutting workability)
Sample No. The workability at the time of removing from the cushion pad mold 11 for each of 10 pieces 1 to 11 was mainly investigated with respect to the working time and evaluated as follows.
：: Workability at the time of die-cutting is particularly good ○: Workability at the time of die-cutting is good ×: Workability at the time of die-cutting is not good Sample molding conditions and evaluation results are as shown in Table 1 below.

この表１から明らかなように、弾性押圧部１５が完全後退する時の、最大充填圧力に対する充填圧力の割合が７５％以上で９５％以下である実施例１〜９では、比較例１，２と比較して、ボイドの発生率が低くかつ抜型時の作業性に優れていることが分かる。

As is clear from Table 1, in Examples 1 to 9 in which the ratio of the filling pressure to the maximum filling pressure when the elastic pressing portion 15 is completely retracted is 75% or more and 95% or less, Comparative Examples 1 and 2 It can be seen that the void generation rate is low and the workability at the time of die cutting is excellent.

  In addition, the place mentioned above only showed an example of embodiment of this invention, and this invention can add a various change within the description range of a claim. For example, in the present embodiment, the pressing plate 15b of the elastic pressing portion 15 is pressed by the coil spring 15c. However, the pressing plate 15b may be pressed by the elastic body 15h surrounding the guide pin 15e. You may press by 15c. Further, the base of the elastic body 15h is fixed in the groove 15d, the top of the elastic body 15h is protruded from the surface of the core mold 13, and the top of the elastic body 15h is directly provided without providing the pressing plate 15b or the cover plate 15g. The reinforcing cloth material 10 may be pressed and bulged.

  Furthermore, in this embodiment, the reinforcing cloth material 10 is formed integrally with the pad main body 9 on the substantially entire back surface side and inside the extended portion of the cushion pad 1, but the reinforcing cloth material 10 is formed only inside the extended portion 5. And the pad main body 9 may be formed integrally, and even if the thick portion 7 is thicker and the extending portion outer side 5a is projected further outward, the effect of the present invention is similarly obtained. can get.

  And as a raw material of a cushion pad, the foamed resin which has the elasticity etc. which exhibit the function as a cushion pad other than the flexible polyurethane foam illustrated by this embodiment can also be used.

  Further, the foamed resin raw material liquid is injected into the cavity by providing an inlet in the upper mold 12 or the lower mold 14 and closing the upper mold 12 and the core mold 13 on the lower mold 14 and then through the inlet. You can go.

  Thus, according to the cushion pad mold of the present invention, the molding failure of the cushion pad can be sufficiently improved by the elastic pressing portion without causing an increase in the manufacturing cost of the cushion pad using the insert material remaining in the cushion pad. Moreover, since the elastic pressing portion is pressed by the foamed resin and retreats, no concave portion remains inside the thick-walled portion, so that a cushion pad made of foamed resin that improves workability at the time of mold removal can be obtained.

  And also by the cushion pad manufacturing method of the present invention, the molding failure of the cushion pad is sufficiently improved by the elastic pressing portion without causing an increase in the manufacturing cost of the cushion pad using the insert material remaining in the cushion pad. Moreover, since the elastic pressing portion is pressed by the foamed resin and retreats, no concave portion remains inside the thick-walled portion, so that a cushion pad made of foamed resin that improves workability at the time of mold removal can be obtained.

DESCRIPTION OF SYMBOLS 1 Cushion pad 2 Cushion pad front side 3 Cushion pad back side 4 Upper edge part 5 Extension part 5a Extension part outer side 5b Extension part inner side 6 Connection part 7 Thick part 8 Thin part 9 Pad body 10 Reinforcement cloth material 10a bulging portion 11 cushion pad forming die 12 upper die 12a step forming portion 12b forming surface 13 core die 13a position for forming the thick portion of the cushion pad 13b forming surface 14 lower die 15 elastic pressing portion 15a spring steel plate 15b pressing plate 15c Coil spring 15d Groove 15e Guide pin 15f Guide hole 15g Cover plate 15h Elastic body 16 Foamed resin raw material liquid PL Parting line

Claims (6)

An extended portion that extends from the upper edge of the foamed cushion pad to the back side and has a U-shaped cross section at the upper portion of the cushion pad, and a connecting portion that extends backward from the upper edge, and the connection A thick-walled portion connected to the portion and a thin-walled portion on the distal end side of the extended portion, and the foamed resin and the reinforcing cloth material covering the foamed resin are integrally formed at least inside the thick-walled portion. A mold for molding a cushion pad,
A lower mold for forming the shape of the front side of the cushion pad;
A core mold for forming the shape of the back surface side of the cushion pad and the shape of the inside of the extended portion;
An upper mold for forming a shape on the back surface side including the outside of the extended portion of the cushion pad;
With
The core mold protrudes from the surface of the core mold by an elastic force, presses the reinforcing cloth material, causes the reinforcing cloth material to bulge into the thick wall portion, and the foamed resin enters the thick wall portion. A cushion pad mold having an elastic pressing part which is pressed by the reinforcing cloth material and retracts when filled.   The cushion pad mold according to claim 1, wherein the elastic pressing portion is configured to bulge the reinforcing cloth material so that the thickness of the thick portion is smoothly connected to the connecting portion.   The cushion according to claim 1 or 2, wherein the elastic pressing portion is retracted along the surface of the core mold when a filling pressure of 75% or more and 95% or less of the maximum filling pressure of the foamed resin is applied. Pad mold.   When the width of the extending portion in the direction orthogonal to the extending direction of the extending portion is L, the width of the elastic pressing portion is at least 0.8 L, and the width direction of the elastic pressing portion The cushion pad mold according to any one of claims 1 to 3, wherein a distance between each of both end portions and the outer surface of the extending portion is 15 mm or more.   The cushion pad mold according to any one of claims 1 to 4, wherein the cushion pad is a back pad for a seat of an automobile. An extended portion that extends from the upper edge of the foamed cushion pad to the back side and has a U-shaped cross section at the upper portion of the cushion pad, and a connecting portion that extends backward from the upper edge, and the connection A thick-walled portion connected to the portion and a thin-walled portion on the distal end side of the extended portion, and the foamed resin and the reinforcing cloth material covering the foamed resin are integrally formed at least inside the thick-walled portion. A method of manufacturing a cushion pad,
A lower mold for forming a shape on the front side of the cushion pad; a core mold for forming a shape on the back surface side of the cushion pad and an inner side of the extending portion; and the extension of the cushion pad. An upper mold for forming a shape on the back side including the outside of the installation part
The core mold protrudes from the surface of the core mold by an elastic force, presses the reinforcing cloth material, causes the reinforcing cloth material to bulge into the thick wall portion, and the foamed resin enters the thick wall portion. Using a cushion pad mold that has an elastic pressing part that is pushed back by the reinforcing cloth material when filled,
When molding the cushion pad with the mold,
The reinforcing cloth material is disposed on at least the surface corresponding to the thick wall portion of the core-shaped surface provided with the elastic pressing portion,
In a state where the reinforcing cloth material is pressed by the elastic pressing portion and bulged from the surface of the core mold, a foamed resin raw material liquid is injected into the mold,
The foamed resin raw material liquid is foamed and filled in the mold, and the elastic pressing part is pressed and retreated with the reinforcing cloth material by the filling pressure in the thick part,
A method of manufacturing a cushion pad, comprising curing the filled foam resin material liquid.

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