JP2003336722A - Crank pulley for engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent deterioration of a damper rubber by heat of an engine while preventing deformation of the damper rubber provided on a crank pulley. <P>SOLUTION: In this crank pulley 19 for an engine, an outer circumferential surface of a hub part 35 fixed to an axial end of a crankshaft 18 protruded from a chain cover 38 is connected to an inner circumferential surface of a circular pulley main body part 36 around which a belt 26 is wound through a circular damper part 37 provided with damper rubbers 42 and 43 capable of absorbing vibration of the crankshaft 18. A stopper member 44 is provided on a side surface on the opposite side of the damper part 37 to the chain cover 38 to restrict excessive deformation of the damper rubber 43, so that a vibration absorbing function and a driving force transmitting function can be securely achieved. Since a stopper member 44 covers only a part of the damper rubber 43, heat radiation is not prohibited, thereby deterioration of the damper rubber 43 by temperature rise is prevented. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an outer peripheral surface of a hub portion fixed to an axial end of a crankshaft protruding from an outer wall portion of an engine and an inner peripheral surface of an annular pulley main body around which a belt is wound. The present invention relates to an engine crank pulley that is connected by an annular damper section that includes a damper rubber that can absorb vibration of a crankshaft.

[0002]

2. Description of the Related Art In a crank pulley which absorbs vibrations of an engine crankshaft and transmits torque of the crankshaft to a belt, a hub fixed to the crankshaft and a pulley body around which the belt is wound are damper rubbers. Those having a structure connected by the method described in Japanese Utility Model Laid-Open No. 6-56553 and Japanese Patent Laid-Open No. 2001-15.
It is known from Japanese Patent No. 9448.

[0003]

By the way, in the one disclosed in Japanese Utility Model Laid-Open No. 6-56553, since the front side of the damper rubber (the side far from the engine body) is open, the crank pulley is not rotated. As a result, the damper rubber deforms so as to jump out to the front side, which may impair the vibration absorbing function and the driving force transmitting function of the crankshaft. On the other hand, the above-mentioned JP 2001-15
The device disclosed in Japanese Patent No. 9448 prevents the deformation of the damper rubber described above because the front and rear surfaces of the damper rubber are blocked, but the heat of the engine is dampened because the periphery of the damper rubber is blocked. There was a possibility that the damper rubber would get stuck around the rubber, and the heat would deteriorate the damper rubber.

The present invention has been made in view of the above circumstances, and an object thereof is to prevent the damper rubber provided on the crank pulley from being excessively deformed and at the same time prevent the damper rubber from being deteriorated by the heat of the engine. And

[0005]

In order to achieve the above object, according to the invention described in claim 1, an outer peripheral surface of a hub portion fixed to an axial end of a crankshaft projecting from an outer wall portion of an engine is provided. In an engine crank pulley in which an inner peripheral surface of an annular pulley main body around which a belt is wound is connected by an annular damper portion provided with a damper rubber capable of absorbing crankshaft vibration, the damper portion is
A crank pulley for an engine is proposed, which is provided with a heat shield wall between the damper rubber and the engine outer wall portion, and a stopper member for suppressing deformation of the damper rubber on a side surface far from the engine outer wall portion. .

According to the above construction, the heat from the engine outer wall is blocked by the heat shield wall, so that not only deterioration of the damper rubber can be prevented but also a damper connecting the hub portion of the crank pulley and the pulley body portion. The deformation of the damper rubber provided on the damper section is suppressed by the stopper member provided on the side surface of the damper section opposite to the engine outer wall section, so the vibration absorbing function and the driving force transmitting function of the damper rubber can be reliably exhibited. it can.

Further, according to the invention described in claim 2,
In addition to the structure of claim 1, there is proposed a crank pulley for an engine, in which a damper rubber is arranged at a position avoiding the inner peripheral surface of the heat shield wall in the damper part.

According to the above construction, since the damper rubber of the damper portion is arranged at a position avoiding the inner peripheral surface of the heat shield wall, it is difficult for the heat of the engine to be transferred to the damper rubber and deterioration is suppressed. In addition, the stopper member can be brought closer to the damper rubber to enhance the deformation suppressing effect.

According to the invention described in claim 3,
In addition to the structure of claim 1 or claim 2, a crank pulley of an engine is proposed in which a damper rubber is arranged at the outer end portion of the inner peripheral surface of the damper portion.

According to the above construction, since the damper rubber is arranged at the outer end portion of the inner peripheral surface of the damper portion, the influence of heat radiation from the engine can be suppressed and the stopper member can be arranged close to the damper rubber. Can be facilitated, and the structure of the stopper member can be prevented from becoming complicated.

According to the invention described in claim 4,
In addition to the structure according to any one of claims 1 to 3, the stopper member includes an annular fixing portion fixed to the hub portion, and a plurality of plates radially extending from the fixing portion along a side surface of the damper rubber. A crankshaft of an engine, characterized in that it has a profile, is proposed.

According to the above construction, since the stopper member has a plurality of plate-shaped portions radially extending along the side surface of the damper rubber from the annular fixing portion fixed to the hub portion, the damper rubber is deformed. In addition to improving the prevention effect, it is possible to radiate heat and to ventilate through the gaps between the adjacent plate-shaped portions, and it is possible to more effectively suppress the temperature rise of the damper rubber.

According to the invention described in claim 5,
In addition to the configuration of claim 4, there is proposed a crank pulley for an engine, characterized in that a plate-shaped portion of a stopper member is twisted to form a cooling fan.

According to the above structure, since the plate-like portion of the stopper member is twisted, the plate-like portion functions as a cooling fan in accordance with the rotation of the crank pulley, so that the damper rubber is exposed to the cooling air. The temperature rise can be suppressed more effectively.

The chain cover 38 of the embodiment corresponds to the engine outer wall portion of the present invention, the side wall 40c of the embodiment corresponds to the heat shield wall of the present invention, and the second damper rubber 43 of the embodiment.
Corresponds to the damper rubber of the present invention.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below based on the embodiments of the present invention shown in the accompanying drawings.

1 to 4 show a first embodiment of the present invention. FIG. 1 is a front view of an engine, FIG. 2 is an enlarged sectional view taken along line 2-2 of FIG. 1, and FIG. 3 is 3 of FIG. -3 line arrow view, FIG. 4 is FIG.
4 is a sectional view taken along line 4-4 of FIG.

As shown in FIG. 1, a diesel engine E for a vehicle is equipped with an accessory bracket 12 attached to a side surface of an engine block 11, and the accessory bracket 12 has an air conditioning compressor 13, a water pump 14, and a generator 15. The idler pulley 16 and the tensioner pulley 17 are supported. Crankshaft 1 of engine E
8 is provided with a crank pulley 19 and an air conditioning compressor pulley 2 is provided with a rotary shaft 20 of the air conditioning compressor 13.
1, a water pump pulley 23 provided on the rotary shaft 22 of the water pump 14, and a rotary shaft 24 of the generator 15.
A belt 26 is wound around the generator pulley 25, the idler pulley 16, and the tensioner pulley 17 provided in the.

As shown in FIGS. 2 to 4, the valve mechanism drive sprocket 31 and the oil pump drive sprocket 32 are integrally formed at the end of the crankshaft 18.
And the crank pulley 19 are fitted together to form a common key 3
3 is non-rotatably coupled, and is secured by a bolt 34 that is screwed onto the shaft end surface of the crankshaft 18. The crank pulley 19 includes a hub portion 35 located inside in the radial direction, a pulley main body portion 36 located outside in the radial direction, and a damper portion 37 connecting the hub portion 35 and the pulley main body portion 36.

The hub portion 35 fixed to the crankshaft 18 with the key 33 and the bolt 34 penetrates the chain cover 38 constituting the engine outer wall portion in the axial direction of the crankshaft 18, and the hub portion 35 and the chain cover 3 are provided.
A seal member 39 is disposed between the seal member 39 and the seal member 8. The pulley main body 36 formed in an annular shape includes a belt engaging portion 36a having a wavy cross section on the outer side in the radial direction and a damper rubber connecting portion 36b on the inner side in the radial direction, and an annular outer peripheral surface of the damper rubber connecting portion 36b. Bearing member 36c is welded. The belt engaging portion 36a with which the inner peripheral surface of the belt 26 engages is only plated with metal (eg, zinc plating), and the remaining metal portion of the crank pulley 19 except the belt engaging portion 36a is plated with the metal. A rust-proof coating is applied on the top.

The damper part 37 has a U-shaped damper mass 40 open to the front side of the crank pulley 19, and a thin-walled cylinder baked on the inner peripheral surface of the inner wall 40a of the damper mass 40 and the outer peripheral surface of the hub part 35. -Shaped first damper rubber 41 and a collar 42 press-fitted on the outer peripheral surface of the inner wall 40a
And an annular second damper rubber 43 baked on the outer peripheral surface of the collar 42 and the inner peripheral surface of the damper rubber coupling portion 36b of the pulley body 36. Damper mass 4
The inner peripheral surface of the outer wall 40b of 0 is slidably fitted to the outer peripheral surface of the bearing member 36c of the pulley body 36, and the pulley body 36 is opposed to the damper portion 37 via the sliding surface. Can rotate.

On the side wall 40c of the damper mass 40 located on the rear side of the crank pulley 19, the crankshaft 1
Two arc-shaped elongated holes 40d, 40d centering on 8 are formed, and two stopper claws protruding from the damper rubber coupling portion 36b of the pulley body 36 in these arc-shaped elongated holes 40d, 40d. 36d and 36d are slidably fitted together. The position of the second damper rubber 43 is displaced from the center of the crank pulley 19 in the thickness direction toward the front side, that is, in the direction away from the side wall 40c of the damper mass 40.

The stopper member 44 attached to the front surface side of the crank pulley 19 includes a short cylindrical fixing portion 44a located at the center and three plate-like portions 44b extending radially from the fixing portion 44a at 120 ° intervals. When the fixing portion 44a is fixed to the inner peripheral surface of the hub portion 35 of the crank pulley 19 by press fitting, the three plate-like portions 44b ... Are the second damper rubber 43 of the damper portion 37 of the crank pulley 19. Is arranged so as to cover the front surface of the.

Even if the fixing portion 44a of the stopper member 44 is attached to the bubbling portion 35, the bolt 34
It may be tightened together. If the structure is such that the crank pulley 19 is attached to the inner surface of the bubbling portion 35 by press fitting or the like, the work of assembling the crank pulley 19 is facilitated and the stopper member 44 is prevented from becoming large because it does not have to have a shape to reach the bolt 34. It is possible and preferable.

Next, the operation of the first embodiment of the present invention having the above construction will be described.

When the crankshaft 18 and the crank pulley 19 rotate with the operation of the engine E, the air conditioning compressor 13, the water pump 14, and the generator 15 are driven via the belt 26. The torque of the crankshaft 18 is the same as that of the hub portion 3 of the crank pulley 19.
5 is transmitted to the pulley main body 36 through the damper portion 37, and at that time, the vibration of the crankshaft 18 is absorbed by the damper portion 37.

That is, the damper mass 40 of the crank pulley 19 and the first damper rubber 41 constitute a dynamic damper, and the elastic deformation of the first damper rubber 41 causes the damper mass 40 to move in the circumferential direction with respect to the hub portion 35. By vibrating, the vibration of the crankshaft 18 in the twisting direction is absorbed. At this time, damper mass 40
The pulley 26 is not directly connected to the pulley main body 36, but is connected via the second damper rubber 43, which has a lower torsional rigidity than the first damper rubber 41, so that the belt 26 inhibits the vibration of the damper mass 40. The function of the dynamic damper can be effectively exhibited without being damaged. Further, since the hub portion 35 and the pulley main body portion 36 are coupled via the second damper rubber 43 having low torsional rigidity, the vibration of the crankshaft 18 is transmitted to the pulley main body portion 36. It can be prevented by elastic deformation of the rubber 43.

If a large torque acts on the crank pulley 19 and the hub portion 35 and the pulley main body portion 36 rotate relative to each other excessively, the second damper rubber 43 may be damaged. Stopper claw 3
6d and 36d are arcuate elongated holes 40d of the damper mass 40,
The second damper rubber 43 is prevented from being damaged because it is regulated by coming into contact with the end of 40d.

Since the second damper rubber 43 has a large area opposed to the chain cover 38, the heat generated by the engine E is easily transferred through the chain cover 38, which may cause deterioration at an early stage. However, the side wall 40c of the damper mass 40 interposed between the chain cover 38 and the second damper rubber 43 functions as a heat shield wall, and the second damper rubber 43 is located on the front side of the crank pulley 19 away from the chain cover 38. Since it is arranged in the above, heat transferred from the chain cover 38 to the second damper rubber 43 can be reduced and deterioration can be suppressed.

When the torque of the engine E is transmitted and the second damper rubber 43 is elastically deformed, the second damper rubber 43 arranged on the front side of the crank pulley 19 is used.
Tends to be further deformed toward the front side of the crank pulley 19. When the second damper rubber 43 is largely deformed in this way, the vibration damping function and the driving force transmitting function of the second damper rubber 43 are impaired. However, according to the present embodiment, the second damper rubber 43 is provided on the front side. The plate-shaped portions 44b of the stopper member 44 provided suppress the excessive deformation of the second damper rubber 43, so that the function of the crank pulley 19 is reliably maintained. Further, since the plate-shaped portions 44b of the stopper member 44 are radially formed and the front surface of the second damper rubber 43 is exposed, the adjacent plate-shaped portions 44b are formed.
It is possible to radiate heat and to ventilate through the gap between the two, and it is possible to more effectively suppress the temperature rise of the second damper rubber 43.

Since the belt engaging portion 36a of the pulley body 36 is only galvanized and not rust-proof coated, the coefficient of friction between the belt 26 and the belt 26 varies due to differences in coating thickness. As a result, uneven driving of the belt 26 can be prevented, and the occurrence of slip noise of the belt 26 can be suppressed. Even if the belt engaging portion 36a is not coated with rust, since it is galvanized, there is no risk of rusting.

Next, a second embodiment of the present invention will be described with reference to FIGS.

In the second embodiment, the plate-like portion 4 of the stopper member 44 is used.
A cooling fan is constructed by twisting 4b. When the crank pulley 19 rotates in the direction of arrow A, the air sucked in the direction of arrow B by the plate-shaped portions 44b hits the second damper rubber 43, forcibly cooling the second damper rubber 43 and preventing deterioration. Can contribute to. Other actions and effects of the second embodiment are as follows.
This is the same as the first embodiment described above.

Although the embodiments of the present invention have been described in detail above, the present invention can be modified in various ways without departing from the scope of the invention.

For example, the plate-like portion 44b of the stopper member 44
The number of is not limited to three in the embodiment and may be any number. Further, by forming the stopper member 44 in a lattice shape or a mesh shape, it is possible to secure the heat dissipation effect while suppressing the deformation of the second damper rubber 43.

Further, the belt engaging portion 3 of the crank pulley 19
6a can be subjected to any kind of plating treatment other than galvanization, and the metal portion of the crank pulley 19 other than the belt engaging portion 36a can be coated only if rust-preventive coating is applied to the outermost surface. It may be.

Although the diesel engine E is illustrated in the embodiment, the present invention can also be applied to a gasoline engine.

The present invention can also be applied to a marine propulsion engine such as an outboard motor having a crankshaft vertically arranged.

[0039]

As described above, according to the invention described in claim 1, since the heat from the engine outer wall is blocked by the heat shield wall, not only deterioration of the damper rubber can be prevented, but also the crank pulley. The deformation of the damper rubber provided in the damper part that connects the hub part and the pulley body part is suppressed by the stopper member provided on the side surface of the damper part opposite to the engine outer wall part, so the vibration absorption function of the damper rubber The drive force transmission function can be reliably exerted.

According to the invention described in claim 2,
Since the damper rubber of the damper part is arranged at a position avoiding the inner peripheral surface of the heat shield wall, not only can the heat of the engine be less transmitted to the damper rubber and deterioration can be suppressed, but also the stopper member can be used as a damper. The rubber can be brought closer to enhance the deformation suppressing effect.

According to the invention described in claim 3,
Since the damper rubber is arranged at the outer end of the inner peripheral surface of the damper part, the influence of heat radiation from the engine can be suppressed, and the stopper member can be easily arranged close to the damper rubber. Can be prevented from becoming complicated.

According to the invention described in claim 4,
Since the stopper member has a plurality of plate-shaped portions radially extending along the side surface of the damper rubber from the annular fixing portion fixed to the hub portion, the deformation preventing effect of the damper rubber is improved and the adjacent portions are provided. It is possible to radiate heat and to ventilate through the gaps between the plate-shaped portions, and to more effectively suppress the temperature rise of the damper rubber.

According to the invention described in claim 5,
Since the plate-shaped part of the stopper member is twisted, the plate-shaped part functions as a cooling fan in accordance with the rotation of the crank pulley, so that the cooling air is applied to the damper rubber and the temperature rise is suppressed more effectively. can do.

[Brief description of drawings]

1] Front view of the engine

FIG. 2 is an enlarged sectional view taken along line 2-2 of FIG.

FIG. 3 is a view taken along the line 3-3 of FIG.

FIG. 4 is a sectional view taken along line 4-4 of FIG.

FIG. 5 is a view corresponding to FIG. 3 according to the second embodiment of the present invention.

6 is a view taken along the line 6-6 of FIG.

[Explanation of symbols]

18 crankshaft 26 belt 35 Hub 36 Pulley body 37 Damper part 38 Chain cover (engine outer wall) 40c Side wall (heat shield wall) 43 2nd damper rubber (damper rubber) 44 Stopper member 44a fixed part 44b Plate part

Claims (5)

[Claims] 1. A hub portion (3) fixed to a shaft end of a crankshaft (18) protruding from an engine outer wall portion (38).
A damper rubber (43) capable of absorbing the vibration of the crankshaft (18) between the outer peripheral surface of 5) and the inner peripheral surface of the annular pulley body (36) around which the belt (26) is wound.
In an engine crank pulley connected by an annular damper part (37) provided with a damper, the damper part (37) includes a heat shield wall (40c) between a damper rubber (43) and an engine outer wall part (38). At the same time, a crank pulley for an engine is provided with a stopper member (44) for suppressing deformation of the damper rubber (43) on a side surface far from the engine outer wall portion (38). 2. A heat shield wall (4) in the damper part (37).
Damper rubber (43) at a position avoiding the inner peripheral surface of
A crank pulley for an engine according to claim 1, wherein the crank pulley is arranged. 3. A damper rubber (43) is arranged at an outer end portion of an inner peripheral surface of the damper portion (37),
The crank pulley of the engine according to claim 1 or 2. 4. The stopper member (44) includes a hub portion (3).
5) An annular fixing portion (44a) fixed to the fixing member (5) and a plurality of plate-like portions (44b) extending radially from the fixing portion (44a) along the side surface of the damper rubber (43). The crank pulley of the engine according to any one of claims 1 to 3. 5. A plate-shaped portion (44) of the stopper member (44).
The crank pulley of the engine according to claim 4, wherein the cooling fan is configured by giving a twist to b).