JP2009270987A - Pressure indicator for gas spring - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an easily handleable pressure indicator for a gas spring and to provide a compact and inexpensive pressure indicator for a gas spring. <P>SOLUTION: This pressure indicator 10 for the gas spring for indicating pressure of the gas stored in a compressed gas filled chamber 3 in the gas spring 1 includes a valve case 11 fixed on the gas spring, a gas filling valve 14 incorporated in the valve case to fill it with compressed gas, a case member 25 fixed on the valve case, a movable pressure receiving member 35 mounted movably in the case member, a gas pressure indicating part 42 formed in a tip part of the movable pressure receiving member to protrude the outside of the case member, a pressure receiving part 38 formed at least at one end of the movable pressure receiving member, a gas pressure application means 45 for applying gas pressure of the compressed gas to the pressure receiving part, and a compression spring 48 for letting elastic force opposing to pressing force of the gas pressure act on the movable pressure receiving member. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a pressure indicator for a gas spring, and more particularly to a gas spring pressure indicator that can visually recognize a decrease in the pressure of a compressed gas contained in a compressed gas filling chamber.

  Conventionally, a gas spring has been widely applied to a spring device having an impact buffering function attached to a press molding device, a punching device, or the like. A general gas spring has a cylinder body, a piston slidably mounted on the cylinder body, a rod portion extending from the piston to the outside of the cylinder body, and the like, and a compressed gas filling chamber filled in the cylinder body. The shock is buffered by the spring action of the gas.

  In general, in a gas spring, compressed gas filled inside leaks minutely from a seal gap or the like, and the gas pressure gradually decreases. Therefore, when the gas pressure of the compressed gas decreases below the set pressure, the compressed gas is additionally filled. Therefore, a digital pressure display device or an analog pressure display device having a pressure sensor for indicating the pressure of compressed gas is often connected to the gas spring. This pressure display device needs to withstand harsh environments such as impact generated by a molding device, a punching device, and the like, chips and oil.

For example, a circuit pressure display device described in Patent Document 1 includes a main body 2, a pressure chamber 6 connected to a gas spring, a piston 3 incorporated in the main body 2 capable of receiving the gas pressure of the pressure chamber 6, It comprises a calibration spring 5 for applying an elastic force to the piston 3 and the like. When the pressing force by the gas pressure is larger than the elastic force of the spring 5, the upper portion 15 of the piston 3 protrudes from the closing lid 14, the gas pressure in the pressure chamber 6 decreases, and the pressing force becomes the elastic force of the spring 5. When it becomes smaller than this, the end surface 16 of the piston 3 becomes the same height as the surface of the closing lid 14 of the main body 2 so that the pressure drop can be visually recognized.
JP 2007-298513 A

  By the way, in order to fill the compressed gas filling chamber of the gas spring of Patent Document 1 with the compressed gas, it is necessary to connect the gas spring to a gas supply source such as a nitrogen gas cylinder through the connecting means of the circuit pressure display device. However, since this connection means is not provided with a gas filling valve, if this circuit pressure display device is separated from the gas supply source after filling with compressed gas, a large amount of compressed gas leaks from the gas filling chamber. Therefore, it is necessary to always connect the circuit pressure display device to the gas supply source even when the gas spring is in operation, which is inconvenient and difficult to install and use in a narrow space.

  In addition, in this circuit pressure display device, the pressing force acting on the piston is enhanced by the high-pressure compressed gas in the gas spring. Therefore, since it is necessary to incorporate a spring member having a strong elastic force in the circuit pressure display device in order to oppose the pressing force, the device becomes large and the manufacturing cost increases.

  An object of the present invention is to provide a gas spring pressure indicator which is excellent in usability, and to provide a gas spring pressure indicator which is excellent in reliability, small and inexpensive.

  The pressure indicator for a gas spring according to claim 1 is a pressure indicator for a gas spring for indicating a pressure of a compressed gas accommodated in a compressed gas filling chamber of the gas spring, and a valve case fixed to the gas spring, and A gas filling valve incorporated in the valve case for filling the gas spring with compressed gas, a case member fixed to the valve case, a movable pressure receiving member movably mounted in the case member, A compressed gas communicated with the compressed gas filling chamber; a gas pressure indicating portion formed at a tip portion of the movable pressure receiving member so as to be able to protrude to the outside of the case member; a pressure receiving portion formed at at least one end of the movable pressure receiving member; A gas pressure acting means for applying a gas pressure of the compressed gas in the introduction passage to the pressure receiving portion; and the movable pressure receiving member according to the gas pressure. A compression spring for applying a pressing force to the opposing elastic force, and comprising the.

  In the gas spring pressure indicator, when the compressed gas filling chamber of the gas spring is filled with the compressed gas through the gas filling valve incorporated in the valve case, the gas pressure acting means is applied to the pressure receiving portion of the movable pressure receiving member. The gas pressure of the compressed gas is applied. Then, a pressing force by the compressed gas that opposes the elastic force of the compression spring acts on the pressure receiving portion, and the amount of protrusion of the gas pressure indicator changes according to the magnitude relationship between the pressing force and the elastic force of the compression spring. To do.

  The pressure indicator for a gas spring according to a second aspect is the pressure indicator for the gas spring according to the first aspect, wherein the movable pressure receiving member is disposed in series with the pressure receiving plunger receiving the gas pressure on one end side and the pressure receiving pressure. And a shaft-shaped member that receives the pressing force from the plunger and receives the elastic force of the compression spring, and the gas pressure indicating portion is formed on the shaft-shaped member.

  According to a third aspect of the present invention, there is provided the gas spring pressure indicator according to the first aspect, wherein the movable pressure receiving member is formed at the first pressure receiving portion at one end thereof and in the middle in the length direction to act on the first pressure receiving portion. It has the 2nd pressure receiving part which is a 2nd pressure receiving part which acts a gas pressure on the opposite direction to a gas pressure, Comprising: A 2nd pressure receiving part smaller than a 1st pressure receiving part is characterized.

  According to a fourth aspect of the present invention, there is provided the gas spring pressure indicator according to the first aspect of the invention, wherein the movable pressure receiving member is formed in the first pressure receiving portion at one end thereof and in the middle in the length direction and acts on the first pressure receiving portion. It has the 2nd pressure receiving part which is a 2nd pressure receiving part which acts a gas pressure on the opposite direction to a gas pressure, Comprising: The 2nd pressure receiving part larger than a 1st pressure receiving part is characterized.

  A pressure indicator for a gas spring according to a fifth aspect is the gas spring pressure indicator according to the second or third aspect, wherein the elastic force of the compression spring is balanced with the pressing force by the gas pressure acting on the movable pressure receiving member. The amount of protrusion by which the indicator protrudes from the surface of the case member is configured to decrease as the gas pressure of the compressed gas decreases.

  According to a sixth aspect of the present invention, there is provided the gas spring pressure indicator according to the fourth aspect of the invention, wherein the elastic force of the compression spring is balanced with the pressing force due to the gas pressure acting on the movable pressure receiving member. However, the amount of protrusion protruding from the surface of the case member increases in accordance with a decrease in the gas pressure of the compressed gas.

  The pressure indicator for a gas spring according to a seventh aspect is characterized in that, in the invention according to any one of the first to sixth aspects, a scale for knowing a protruding amount from the surface of the case member is marked on the gas pressure indicating portion. It is said.

  The pressure indicator for a gas spring according to claim 8 is characterized in that, in the invention of claim 2, a seal member with a lip is provided in contact with one end of the pressure receiving plunger.

  A pressure indicator for a gas spring according to a ninth aspect is the invention according to the second or eighth aspect, wherein a communication passage formed in the valve case so as to introduce a gas pressure from the gas pressure introduction path in the valve case to the pressure receiving portion; In addition, a metal ring member that is externally fitted to the valve case is provided so that a downstream end of the communication path serves as a throttle path.

  According to the invention of claim 1, a valve case, a gas filling valve incorporated in the valve case, a case member, a movable pressure receiving member, a gas pressure indicating portion, a pressure receiving portion, a gas pressure acting means, When the compressed gas filling chamber is filled with the compressed gas through the gas filling valve, the gas pressure acts on the pressure receiving portion of the movable pressure receiving member, and the pressure receiving portion receives the compression spring. The pressing force opposite to the elastic force acts, and the movable pressure receiving member moves according to the magnitude relationship between the pressing force by the compressed gas and the elastic force of the compression spring, and the gas pressure indicator moves. The decrease in gas pressure can be easily recognized visually.

  Since the gas filling valve is incorporated in the valve case, the pressure indicator for the gas spring can be separated from the gas supply source after the compressed gas filling chamber is filled with the compressed gas, thereby improving the usability of the gas spring and handling. It becomes easy.

  According to a second aspect of the present invention, the movable pressure receiving member is disposed in series on the other end side of the pressure receiving plunger that receives the gas pressure on one end side, and receives the pressing force from the pressure receiving plunger. Since the gas pressure indicating portion is formed on the shaft-like member, the shape of each member constituting the movable pressure-receiving member is simplified, and can be easily manufactured and moved. The pressure receiving member can be easily incorporated into the case member.

  According to a third aspect of the present invention, the movable pressure receiving member has a gas pressure in a direction opposite to the first pressure receiving portion at one end thereof and the gas pressure that is formed in the middle in the length direction and acts on the first pressure receiving portion. Since it has the 2nd pressure receiving part which is the 2nd receiving pressure part made to act and has a receiving pressure area smaller than the 1st receiving pressure part, the pressing force by the gas pressure which acts on the 1st receiving pressure part, and the gas pressure which acts on the 2nd receiving pressure part This balances the differential force with the pressing force due to the elastic force of the compression spring. Therefore, the elastic force of the compression spring can be reduced, the pressure indicator for the gas spring can be reduced in size, and the manufacturing cost can be reduced.

  According to the invention of claim 4, the movable pressure receiving member has a gas pressure in a direction opposite to the first pressure receiving portion at one end thereof and the gas pressure that is formed in the middle portion in the length direction and acts on the first pressure receiving portion. Since the second pressure receiving portion is a second pressure receiving portion having a larger pressure receiving area than that of the first pressure receiving portion, the elastic force of the compression spring can be reduced as in the third aspect. The pressure indicator can be miniaturized and the manufacturing cost can be reduced. And since it can comprise so that the protrusion amount of the gas pressure instruction | indication part to the exterior of a case member may become large according to the fall of a gas pressure, it becomes easy to recognize the fall of a gas pressure.

  According to a fifth aspect of the present invention, the elastic force of the compression spring is configured to be balanced with the pressing force by the gas pressure acting on the movable pressure receiving member, and the gas pressure indicator protrudes from the surface of the case member. Since the protrusion amount is configured to decrease in accordance with a decrease in the gas pressure of the compressed gas, there is a possibility that the decrease in the gas pressure can be easily grasped from the protrusion amount.

  According to the invention of claim 6, the elastic force of the compression spring is configured to be balanced with the pressing force due to the gas pressure acting on the movable pressure receiving member, and the gas pressure indicator protrudes from the surface of the case member. Since the protruding amount is configured to increase in accordance with the decrease in the gas pressure of the compressed gas, the gas pressure indicating portion is displayed with a color such as blue, yellow, red, etc. It is advantageous.

  According to the seventh aspect of the invention, since the scale for knowing the amount of protrusion from the surface of the case member is marked on the gas pressure indicating portion, the degree of decrease in the gas pressure of the compressed gas in the gas spring is determined from the scale. It can be made recognizable.

  According to the eighth aspect of the present invention, since the seal member with the lip is provided in contact with the one end of the pressure receiving plunger, when the pressing force by the gas pressure is applied to the lip portion, the pressing force acts from the inside to the outside of the lip portion. And the gas tightness of the pressure indicator for gas springs can be improved by opening a lip | rip part.

  According to the ninth aspect of the present invention, the communication passage formed in the valve case so as to introduce the gas pressure from the gas pressure introduction passage in the valve case to the pressure receiving portion, and the downstream end of the communication passage is defined as the throttle passage. Since the metal ring member externally fitted to the valve case is provided, the gas pressure that frequently fluctuates in the operating gas spring does not directly act on the movable pressure receiving member. Is suppressed, and wear of the seal member can be suppressed.

  Hereinafter, the best mode for carrying out the present invention will be described based on examples.

First, the gas spring 1 to which the present invention is applied will be described.
As shown in FIGS. 1 to 3, the gas spring 1 includes a cylinder body 3, a compressed gas filling chamber 4 provided in the cylinder body 3, and a piston 6 slidably fitted in the cylinder body 3. The rod portion 7 and the like extending from the piston 6 to the outside of the cylinder body 3 are configured so as to buffer the impact by the spring action of the compressed gas filled in the cylinder body 3. The cylinder body 3 includes a mounting portion 3 a to which the gas spring pressure indicator 10 is mounted and a gas supply hole 3 b that communicates with the compressed gas filling chamber 4.

Next, the pressure indicator 10 for gas springs of the present invention will be described.
As shown in FIGS. 1 to 3, the gas spring pressure indicator 10 (hereinafter, abbreviated as “pressure indicator”) is used to indicate the pressure of the compressed gas stored in the compressed gas filling chamber 4 of the gas spring 1. . The pressure indicator 10 includes a valve case 11, a gas filling valve 14, a case member 25, a movable pressure receiving member 35, a pressure receiving portion 38, a gas pressure indicating portion 42, a gas pressure acting means 45, and a compression spring 48. And. In the following description, the top, bottom, left, and right in FIG.

As shown in FIG. 1, the valve case 11 is a member integrally formed with three parts, that is, a front end part 11 a, an intermediate part 11 b, and a rear end part 11 c, and is fixed to the gas spring 1. A gas pressure introduction path 12 is formed in the valve case 11 so as to penetrate in the left-right direction. A gas filling valve 14 is incorporated in the gas pressure introduction path 12 so as to fill the gas spring 1 with compressed gas. Yes. Since the gas filling valve 14 is incorporated in the valve case 11, the pressure indicator 10 can be used separately from the gas supply source after the compressed gas filling chamber 4 is filled with the compressed gas. Is improved, and it becomes possible to use it in a small space. The outer peripheral portion of the tip portion 11 a is formed as a male screw and is screwed into a mounting portion 3 a formed in the cylinder body 3. A seal member 15 for keeping gas tightness is attached to a boundary portion between the tip portion 11a and the intermediate portion 11b.

  A communication passage 16 and an annular groove 17 are formed in the intermediate portion 11 b of the valve case 11. The communication path 16 is formed to be orthogonal to the gas pressure introduction path 12. Gas pressure is introduced from the gas pressure introduction passage 12 in the valve case 11 to the pressure receiving portion 38 through the communication passage 16 and the annular groove 17. An annular groove 17 is formed at the position of the communication path 16 on the outer peripheral portion of the intermediate portion 11 b, and a metal ring member 18 is fitted around the annular groove 17. A plurality of seal members 19a and 19b are mounted on the right side of the metal ring member 18, and 19c and 19d are mounted on the left side. By the ring member 18, the downstream end of the communication path 16 is configured as a throttle path. An annular rubber member 21 is fitted on the outer peripheral surface of the intermediate portion 11b on the gas spring 1 side, and is fixed via a stop ring 21a.

  The outer peripheral portion of the rear end portion 11c of the valve case 11 is formed in a hexagonal shape, and when the gas spring 1 is fixed, the front end portion 11a is attached to the mounting portion 3a by engaging the tool with the rear end portion 11c and rotating the tool. Screw on. A plug 23 that closes the gas pressure introduction path 12 is attached to the opening of the gas pressure introduction path 12. The plug 23 is provided with a seal member 23a for keeping the gas pressure introduction path 12 gas tight.

Next, the case member 25 will be described.
As shown in FIG. 1, the case member 25 includes a base member 26 that is externally fitted and fixed to the valve case 11, and a cylindrical member 29, and the case member 25 is interposed via the base member 26. Is erected. A movable pressure receiving member 35 and a compression spring 48 described later are provided inside the case member 25.

  The base member 26 is formed with a through hole 27a into which the valve case 11 is fitted, and a through hole 27b orthogonal to the through hole 27a. The through-hole 27a is formed horizontally in the left-right direction in the lower step portion 26a of the base member 26, and the base member 26 is inserted into the through-hole 27a so as to be fitted into the intermediate portion 11b of the valve case 11. Is fixed between the step ring at the boundary between the rear end portion 11c and the stop ring 21a.

  The through hole 27b is formed in the upper portion 26b of the base member 26 in the vertical direction, and the pressure receiving plunger 36 is slidably inserted into the through hole 27b. In this through hole 27 b, the space facing the pressure receiving plunger 36 is a pressure receiving chamber 28 for applying a pressing force by gas pressure to the pressure receiving portion 38 of the pressure receiving plunger 36. At least one drain groove 26 c is formed on the upper end surface of the base member 26.

  The cylindrical member 29 is composed of a main body cylindrical portion 29 a and a top wall portion 29 b, and a lower end portion of the main body cylindrical portion 29 a is externally screwed onto the upper portion of the base member 26. A drain port 31 is formed at a position slightly lower than the upper end surface of the base member 26 on the side surface of the main body cylinder portion 29a. The top wall portion 29b is provided with a through hole 30 extending in the vertical direction, and a distal end portion 41b of the movable pressure receiving member 35 is movably inserted into the through hole 30 so as to protrude outward. A guide member 30 a and a dust seal 32 for receiving a load in the thrust direction of the tip portion 41 b of the shaft-like member 41 are mounted in the through hole 30.

Next, the movable pressure receiving member 35 will be described.
As shown in FIG. 1, the movable pressure receiving member 35 includes a pressure receiving plunger 36 that receives gas pressure on one end side, and a shaft-like member 41 that is arranged in series on the other end side, and is movable within the case member 25. It is attached to. The pressure receiving plunger 36 is a cylindrical member, and the upper portion of the pressure receiving plunger 36 is inserted into and in contact with the vertical hole in the lower end portion of the shaft-shaped member 41. The lower end surface of the pressure receiving plunger 36 is a pressure receiving portion 38 where the gas pressure of the compressed gas acts.

  The shaft-like member 41 is formed by integrally forming a main body portion 41a, a small-diameter shaft portion 41b and a flange portion 41c at the tip portion. A pressing force due to gas pressure acts on the shaft-like member 41 from the lower pressure receiving plunger 36, and the elastic force of the compression spring 48 acts from above. The small-diameter shaft portion 41b is formed to have a slightly smaller diameter than the main body portion 41a, and a gas pressure instruction portion 42 is formed on the small-diameter shaft portion 41b at a portion protruding to the outside of the case member 25.

  The lower end of the compression spring 48 abuts on the annular upper end surface of the flange 41c of the shaft member 41, the shaft member 41 is elastically biased downward, and the lower end surface of the flange 41c is above the base member 26. It is in contact with the end face. A plurality of prevention grooves 43 that prevent the shaft-like member 41 from adhering to the base member 26 are formed on the lower end surface of the flange portion 41c.

  The gas pressure instruction | indication part 42 is formed in the part which protrudes from the case member 25 among the small diameter shaft parts 41b. For example, a green mark is marked on the outer peripheral surface of the gas pressure indicator 42 to indicate a normal pressure state, and a red mark is marked on the tip surface of the gas pressure indicator 42 to indicate an abnormal pressure state. it can. As shown in FIG. 5, instead of the colored mark as described above or together with the colored mark, a scale 42a for reading the amount of protrusion from the surface of the case member 25 of the gas pressure indicating portion 42 and a number indicating the gas pressure However, the outer peripheral surface of the gas pressure instruction unit 42 may be marked.

  The gas pressure acting means 45 acts on the pressure receiving portion 38 with the gas pressure of the compressed gas in the compressed gas introduction passage 12 communicating with the compressed gas filling chamber 4 of the gas spring 1, and is connected to the valve case 11. The passage 16, the annular groove 17, and the pressure receiving chamber 28 in the through hole 27 b of the case member 25 are configured.

  The compression spring 48 is disposed on the outer peripheral side of the shaft-like member 41 in the case member 25, and the upper end abuts on the top wall portion 29 b of the case member 25 and the lower end abuts on the flange portion 41 c of the shaft-like member 41. Then, an elastic force opposite to the pressing force by the gas pressure is applied to the movable pressure receiving member 35. As described above, the pressure indicator 10 is configured so that the elastic force of the compression spring 48 is balanced with the pressing force by the gas pressure acting on the movable pressure receiving member 35, and the gas pressure indicator 42 protrudes from the surface of the case member 25. The protruding amount is reduced in accordance with the decrease in the gas pressure of the compressed gas.

  As shown in FIG. 1, a lip-attached seal member 49 is provided in contact with the lower end surface of the pressure receiving plunger 36. As shown in FIG. 4, the seal member 49 with a lip is composed of a seal body 49a and a lip 49b. When gas pressure acts on the lip 49b from below, the lip 49b is pressed from the inside to the outside, Since the lip portion 49b opens, the sliding gap between the through hole 27b is closed and the gas pressure is sealed.

Here, the relationship between the protrusion amount of the gas pressure instruction | indication part 42 and gas pressure is demonstrated.
The gas spring 1 is assumed to have, for example, three types of 8 MPa specification, 10 MPa specification, and 12 MPa specification that have different gas pressures of the compressed gas to be filled. FIG. 6 shows set values relating to the protrusion amount of the gas pressure indicator 42 when compression springs of 8 MPa specification, 10 MPa specification, and 12 MPa specification are applied as the compression spring 48, respectively. In addition, the maximum protrusion amount of the gas pressure instruction | indication part 42 is set, for example to 3 mm.

  When an 8 MPa specification spring is applied to the compression spring 48, the gas pressure indicator 42 protrudes a maximum of 3 mm when the gas pressure is 8 MPa, and the protrusion amount becomes 0 mm when the gas pressure decreases to 6.6 MPa. When a 10 MPa specification spring is applied to the compression spring 48, the gas pressure indicator 42 protrudes a maximum of 3 mm when the gas pressure is 10 MPa, and the protrusion amount becomes 0 mm when the gas pressure decreases to 8.5 MPa. When a 12 MPa type spring is applied to the compression spring 48, the gas pressure indicator 42 protrudes by a maximum of 3 mm when the gas pressure is 12 MPa, and the protrusion amount becomes 0 mm when the gas pressure decreases to 10 MPa.

Next, the operation and effect of the pressure indicator 10 will be described.
First, in the pressure indicator 10, the compressed gas gas pressure does not act on the pressure receiving portion 38 of the pressure receiving plunger 36 when the gas filling chamber 4 of the gas spring 1 is not filled with the compressed gas. Is at the lowest position by the elastic force of the compression spring 48. Therefore, the front end surface of the gas pressure instruction unit 42 is at the same height as the upper end surface of the case member 25, and the gas pressure instruction unit 42 is in a retracted state in the case member 25.

  Next, when the compressed gas is filled into the gas filling chamber 4 from a gas supply source such as a nitrogen cylinder, the gas supply source is connected to the gas filling valve 14 via the gas hose, and the compressed gas is filled into the gas filling chamber 4. . In this case, the compressed gas having a pressure corresponding to the setting specification of the gas pressure of the gas spring 1 is filled. Then, the gas pressure acts on the pressure receiving portion 38 of the pressure receiving plunger 36 via the gas action means 45, and the compression spring 48 is elastically deformed until the pressing force by the gas pressure and the elastic force of the compression spring 48 are balanced. The gas pressure indicator 42 protrudes to the maximum (for example, 3 mm).

  Thereafter, when the gas spring 1 is used in a state separated from the gas supply source, the gas pressure in the gas filling chamber 4 gradually decreases due to the leak of the compressed gas, so that the pressing force to the pressure receiving portion 38 gradually decreases. Then, the gas pressure instruction part 42 gradually retracts into the case member 25. Thus, since the protrusion amount of the gas pressure instruction | indication part 42 reduces according to the fall of gas pressure, the fall of gas pressure can be recognized visually easily. Here, when the scale 42a for knowing the amount of protrusion from the surface of the case member 25 and the number indicating the gas pressure are marked on the gas pressure instruction section 42, the approximate value of the gas pressure is recognized by a specific numerical value. can do.

  Here, the movable pressure receiving member 35 has a pressure receiving plunger 36 that receives gas pressure on one end side, and is arranged in series on the other end side and receives a pressing force from the pressure receiving plunger 36 and receives the elastic force of the compression spring 48. Since the shaft-shaped member 41 is provided and the gas pressure indicator 42 is formed on the shaft-shaped member 41, the shape of the individual members constituting the movable pressure-receiving member 35 is simplified, and can be manufactured easily and inexpensively. Since the lip-attached seal member 49 is provided at one end of the pressure receiving plunger 36, the sealing performance of the pressure receiving portion 38 can be improved.

  Moreover, the communication passage 16 formed in the valve case 11 so as to introduce the gas pressure from the gas pressure introduction passage 12 in the valve case 11 to the pressure receiving portion 38, and the downstream end of the communication passage 16 is used as a throttle passage. Since the metal ring member 18 fitted on the valve case 11 is provided, even if the gas pressure of the gas spring 1 frequently changes during operation, the gas pressure acting on the pressure receiving portion 38 is an averaged gas. Since the vertical pressure of the movable pressure receiving member 35 is suppressed, wear of the guide member 30a, the dust seal 32, the seal member 49 with a lip, and the like can be suppressed.

  An example in which the first embodiment is partially changed will be described. However, the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted. As shown in FIG. 7, a gas working chamber 50 is formed inside the case member 25A of the pressure indicator 10A, and a movable pressure receiving member 35A consisting of one member and a compression spring 48A are provided.

  The case member 25 </ b> A includes a base member 56 and a cylindrical member 59. The base member 56 is formed with a through hole 27a into which the valve case 11 is inserted and a through hole 57a having a slightly larger diameter than the through hole 27b of the first embodiment. The through hole 57 a is for introducing the compressed gas from the gas introduction path 12 through the communication path 16 to the gas working chamber 50. The gas action means 45 </ b> A includes a communication path 16 and an annular groove 17 formed in the valve case 11, a through hole 57 a, and a gas working chamber 50.

  The cylindrical member 59 is formed by integrally forming a main body cylindrical portion 59a and a top wall portion 59b. A seal member 63 a for holding the gas working chamber 50 in a gas-tight manner is mounted between the lower end portion of the main body cylinder portion 59 a and the base member 56. In the through hole 60 of the top wall portion 59b, a plurality of seal members 63b and 63c for holding the gas working chamber 50 in a gas-tight manner are mounted in the sliding gap between the top wall portion 59b and the tip portion 71b. .

  The movable pressure receiving member 35A is formed by integrally forming a main body portion 71a, a small diameter shaft portion 71b, and a flange portion 71c. The movable pressure receiving member 35 </ b> A includes a first pressure receiving portion 73 at one end thereof and a second pressure receiving portion 74 that is formed in the middle in the length direction and applies a gas pressure in a direction opposite to the gas pressure acting on the first pressure receiving portion 73. The second pressure receiving portion 74 has a pressure receiving area smaller than that of the first pressure receiving portion 73. The gas pressure instruction portion 42A is formed in a portion of the small diameter shaft portion 71b that protrudes from the case member 25A due to the pressing force of the compressed gas.

  The first pressure receiving portion 73 is a circular lower end surface of the flange portion 71c, and the second pressure receiving portion 74 includes an annular upper end surface of the flange portion 71c and an annular upper end surface of the main body portion 71a. Since there is a sliding gap between the outer peripheral surface of the flange portion 71c and the inner peripheral surface of the case member 25A, when compressed gas is introduced into the through hole 57a, the compressed gas is also introduced into the gas working chamber 50, A gas pressure acts on the first pressure receiving portion 73 and the second pressure receiving portion 74, and a pressing force due to the gas pressure acts respectively.

  In this movable pressure receiving member 35 </ b> A, a part of the pressure receiving area of the first pressure receiving portion 73 is canceled by the pressure receiving area of the second pressure receiving portion 74, so that the pressure receiving area of the first pressure receiving portion 73 and the pressure receiving area of the second pressure receiving portion 74 are The pressing force of the compressed gas acts upward on the circular pressure receiving portion 76 (the pressure receiving portion that receives the pressure receiving area equal to the cross-sectional area of the small-diameter shaft portion 71b on the lower end surface of the flange portion 71c) having the difference area.

  The compression spring 48A is disposed on the outer peripheral side of the movable pressure receiving member 35A, and has an upper end in contact with the top wall portion 59b of the case member 25A and a lower end in contact with the upper end surface of the flange portion 71c of the movable pressure receiving member 35A. The elastic force that opposes the pressing force by the gas pressure acts downward on the movable pressure receiving member 35A.

  As described above, in the pressure indicator 10A, the elastic force of the compression spring 48A is configured to balance the pressing force by the gas pressure acting on the circular pressure receiving portion 76 of the movable pressure receiving member 35A. Similarly, the amount of protrusion by which the gas pressure indicator 42A protrudes from the surface of the case member 25A is configured to decrease in accordance with the decrease in the gas pressure of the compressed gas. Can be recognized.

  The movable pressure receiving member 35 </ b> A includes a first pressure receiving portion 73 at one end thereof and a second pressure receiving portion 74 that is formed in the middle in the length direction and applies a gas pressure in a direction opposite to the gas pressure acting on the first pressure receiving portion 73. Since the second pressure receiving portion 74 has a pressure receiving area smaller than that of the first pressure receiving portion 73, the differential force between the pressing force acting on the first pressure receiving portion 73 and the pressing force acting on the second pressure receiving portion 74; The structure is such that the elastic force of the compression spring 48A is balanced. Therefore, since the elastic force of the compression spring 48A can be remarkably reduced, the compression spring 48A can be downsized, and the pressure indicator 10A can be downsized and the manufacturing cost can be reduced. Other configurations, operations, and effects are the same as those in the first embodiment.

  An example in which the first embodiment is partially changed will be described. However, the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted. As shown in FIG. 8, a gas working chamber 50B is formed inside the case member 25B of the pressure indicator 10B, and a movable pressure receiving member 35B, a compression spring 48B, and a rod member 81 are provided.

  The case member 25 </ b> B includes a base member 86 and a cylindrical member 89. The base member 86 is formed with a through hole 27a into which the valve case 11 is inserted and a through hole 87a to which the rod member 81 is fixed. The rod member 81 is formed with a vertical through hole 81a and a horizontal through hole 81b orthogonal to the through hole 81a. These through holes 81a and 81b are for introducing the compressed gas from the gas introduction path 12 through the communication path 16 to the gas working chamber 50B. A plurality of seal members 81 c and 81 d are mounted on the upper portion of the rod member 81. The gas action means 45B includes the communication passage 16 and the annular groove 17 formed in the valve case 11, the through hole 87b, the through holes 81a and 81b, and the gas working chamber 50B.

  The tubular member 89 is formed by integrally forming a main body tubular portion 89a and a top wall portion 89b. A seal member 93 a for holding the gas working chamber 50 </ b> B in a gas-tight manner is mounted between the lower end portion of the main body cylinder portion 89 a and the base member 86. In the through-hole 90 of the top wall 89b, a plurality of seal members 93b and 93c for sealing the gas working chamber 50B in a gas-tight manner are mounted in the sliding gap between the top wall 89b and the small-diameter shaft portion 101b. Yes.

  The movable pressure receiving member 35B is formed by integrally forming a disc portion 101a, a small diameter shaft portion 101b, and a cylindrical portion 101c. The upper portion of the rod member 81 is slidably and gastightly inserted into the cylinder hole 102a of the cylindrical portion 101c. The inside of the cylinder hole 102a communicates with the atmosphere via a small diameter hole 102b formed in the small diameter shaft portion 101b and an air hole 102c. The gas pressure instruction portion 42B is formed in a portion of the small diameter shaft portion 101b that protrudes from the case member 25B due to the pressing force of the compressed gas.

  The movable pressure receiving member 35B includes a first pressure receiving portion 73B at one end thereof and a second pressure receiving portion 74B that is formed in the middle in the length direction and applies a gas pressure in a direction opposite to the gas pressure acting on the first pressure receiving portion 73B. The second pressure receiving portion 74B has a larger pressure receiving area than the first pressure receiving portion 73B. Note that there is a gas passage gap between the outer peripheral surface of the disc portion 101a and the inner peripheral surface of the main body cylinder portion 89a. A groove 103 is also formed on the upper surface of the disk portion 101a.

  The first pressure receiving portion 73B includes an annular lower end surface of the cylindrical portion 101c and an annular lower end surface of the disc portion 101a, and the second pressure receiving portion 74B is configured by an annular upper end surface of the disc portion 101a. Yes. When compressed gas is introduced into the gas working chamber 50B, the gas pressure of the compressed gas acts on the first pressure receiving portion 73B and the second pressure receiving portion 74B, and the pressing force due to these gas pressures acts respectively.

  In this movable pressure receiving member 35B, most of the pressure receiving area of the second pressure receiving portion 74B is canceled by the pressure receiving area of the first pressure receiving portion 73B, and therefore the pressure receiving area of the second pressure receiving portion 74B and the pressure receiving pressure of the first pressure receiving portion 73B. Compressed gas acts on the annular pressure receiving portion 106 (pressure receiving portion that applies gas pressure to the upper end surface of the disc portion 101a) having a pressure receiving area that is different from the area, and the pressing force acts downward.

  The compression spring 48B is disposed on the outer peripheral side of the movable pressure receiving member 35B, the upper end abuts on the lower end surface of the disc portion 101a of the movable pressure receiving member 35B, the lower end abuts on the upper end surface of the base member 86, and the movable pressure receiving member 35B. On the other hand, an elastic force opposite to the pressing force by the gas pressure is applied upward.

  Thus, the pressure indicator 10B is configured so that the elastic force of the compression spring 48B is balanced with the pressing force by the gas pressure acting on the movable pressure receiving member 35B, and the amount of protrusion protruding from the surface of the case member 25B is the amount of compressed gas. Since the amount of protrusion of the gas pressure instruction section 42B increases as the gas pressure decreases, the degree of decrease in the gas pressure can be visually recognized. Here, when a red mark is marked on the outer peripheral surface of the gas pressure instruction section 42B, the amount of protrusion of the red mark increases as the gas pressure decreases, so that the warning effect is enhanced.

  Since the structure is such that the pressing force acting on the first pressure receiving portion 73B, the downward differential force of the pressing force acting on the second pressure receiving portion 74B, and the upward elastic force of the compression spring 48B are balanced, Example 2 Similarly, the compression spring 48B can be downsized, and the pressure indicator 10B can be downsized and the manufacturing cost can be reduced. Other configurations, operations, and effects are the same as those in the first embodiment.

Next, a modified example in which the above embodiment is partially modified will be described.
1] If the maximum protrusion amount from the case member of the gas pressure instructing portions 42, 42A, 42B can be easily known visually, the protrusion amount can be appropriately changed according to the specification of the pressure indicator. good.
2] Metal ring members may be fitted around the annular grooves 17 of the pressure indicators 10A and 10B.
3] In addition, those skilled in the art can implement the present invention with various modifications added thereto without departing from the spirit of the present invention.

It is a longitudinal cross-sectional view of the gas spring and pressure indicator which concern on Example 1 of this invention. It is a top view of a gas spring and a pressure indicator. It is a perspective view of a gas spring and a pressure indicator. It is a longitudinal cross-sectional view of the sealing member with a lip. It is a principal part enlarged view of the gas pressure instruction | indication part of the modification of a pressure indicator, and its peripheral part. It is a diagram which shows the setting value of the protrusion amount of the gas pressure instruction | indication part corresponding to a gas pressure. It is a longitudinal cross-sectional view of the gas spring and pressure indicator which concern on Example 2. FIG. It is a longitudinal cross-sectional view of the gas spring and pressure indicator which concern on Example 3. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Gas spring 4 Compressed gas filling chamber 10, 10A, 10B Gas spring pressure indicator 11 Valve case 12 Gas pressure introduction path 14 Gas filling valve 16 Communication path 17 Annular groove 18 Metal ring members 25, 25A, 25B Case member 26 Base Member 28 Pressure receiving chamber 29 Cylindrical members 35, 35A, 35B Movable pressure receiving member 36 Pressure receiving plunger 38 Pressure receiving portion 41 Shaft shaped members 42, 42A, 42B Gas pressure indicating portions 45, 45A, 45B Gas pressure acting means 48, 48A, 48B Compression Spring 49 Lip seal member 50, 50B Gas working chamber 73, 73B First pressure receiving portion 74, 74B Second pressure receiving portion 76 Circular pressure receiving portion 106 Annular pressure receiving portion

Claims (9)

In the pressure indicator for a gas spring for indicating the pressure of the compressed gas stored in the compressed gas filling chamber of the gas spring,
A valve case fixed to the gas spring, and a gas filling valve incorporated in the valve case to fill the gas spring with compressed gas;
A case member fixed to the valve case;
A movable pressure receiving member movably mounted in the case member;
A gas pressure indicating portion formed at a tip portion of the movable pressure receiving member so as to be able to protrude to the outside of the case member;
A pressure receiving portion formed on at least one end of the movable pressure receiving member;
Gas pressure acting means for causing the pressure receiving portion to act on the pressure receiving portion of the compressed gas in the compressed gas introduction passage communicating with the compressed gas filling chamber;
A compression spring that applies an elastic force opposite to the pressing force by the gas pressure to the movable pressure receiving member;
A pressure indicator for a gas spring, characterized by comprising:   The movable pressure receiving member has a pressure receiving plunger that receives the gas pressure on one end side, and a shaft that is arranged in series on the other end side and receives the pressing force from the pressure receiving plunger and receives the elastic force of the compression spring. The gas spring pressure indicator according to claim 1, wherein the gas pressure indicator is formed on a shaft-like member.   The movable pressure receiving member is a first pressure receiving portion at one end thereof, and a second pressure receiving portion that is formed in the middle in the length direction and applies a gas pressure in a direction opposite to the gas pressure acting on the first pressure receiving portion. The pressure indicator for a gas spring according to claim 1, further comprising a second pressure receiving portion having a pressure receiving area smaller than that of the first pressure receiving portion.   The movable pressure receiving member is a first pressure receiving portion at one end thereof, and a second pressure receiving portion that is formed in the middle in the length direction and applies a gas pressure in a direction opposite to the gas pressure acting on the first pressure receiving portion. The pressure indicator for a gas spring according to claim 1, further comprising a second pressure receiving portion having a larger pressure receiving area than the first pressure receiving portion.   The elastic force of the compression spring is configured to be balanced with the pressing force by the gas pressure acting on the movable pressure receiving member, and the amount of protrusion by which the gas pressure indicator protrudes from the surface of the case member is the gas pressure of the compressed gas. The pressure indicator for a gas spring according to claim 2 or 3, wherein the pressure indicator is configured to decrease in accordance with a decrease in the pressure.   The elastic force of the compression spring is configured to be balanced with the pressing force by the gas pressure acting on the movable pressure receiving member, and the amount of protrusion by which the gas pressure indicator protrudes from the surface of the case member is the gas pressure of the compressed gas. The gas spring pressure indicator according to claim 4, wherein the gas spring pressure indicator is configured to increase in accordance with a decrease in the pressure.   The pressure indicator for a gas spring according to any one of claims 1 to 6, wherein a scale for knowing an amount of protrusion from the surface of the case member is marked on the gas pressure indicator.   The pressure indicator for a gas spring according to claim 2, wherein a seal member with a lip is provided in contact with one end of the pressure receiving plunger.   A communication passage formed in the valve case so as to introduce a gas pressure from the gas pressure introduction passage in the valve case to the pressure receiving portion, and an outer fitting to the valve case so that a downstream end of the communication passage serves as a throttle passage. The pressure indicator for gas springs according to claim 2 or 8, wherein the metal ring member is provided.