JP2005265029A - Support device for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make forming of support device for a vehicle easy and to enable to retain elastic characteristics of each part in a bushing axial direction of the support device uniform even in such case. <P>SOLUTION: In the support device 1, a pivot cylinder body 8 supporting a support arm 2 pivotally around a pivot axial center 6 in relation to a vehicle body 3 is provided with an elastic bushing 12 rotatable around the pivot axial center 6 and an outer tube 13 in which the busing 12 is pressed in. The outer tube 12 is made by casting, a middle part 17 in an axial direction of an inner circumference surface 15 of the outer tube 13 has a shape roughly parallel with the pivot axial center 6 and each end part 18, 19 in an axial direction has tapered shape enabling mold omission toward one direction A of each axial direction. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a support device in a vehicle including a pivot cylinder that enables a support arm to pivot on a vehicle body side.

  As an example of the support device in the vehicle, conventionally, a suspension device that suspends wheels on a vehicle body is disclosed in Patent Document 1 below. According to this publication, the suspension device includes a pivot shaft that is supported on the vehicle body side, and a pivot that is fitted around the pivot shaft so as to be rotatable about the pivot shaft center of the pivot shaft. A support cylinder body, and the pivot cylinder body is fitted around the pivot shaft and is fixedly fitted around the inner cylinder, and rotates around the pivot axis together with the inner cylinder. The elastic bushing which is made possible and an outer cylinder which press-fits the bush and supports a support arm which supports the wheel are provided.

  When the vehicle travels, the support arm swings up and down according to the unevenness of the traveling road surface, and the impact force that is applied to the vehicle from the traveling road surface is reduced. Further, an impact force that is transmitted from the support arm side to the vehicle body side is alleviated by elastic deformation of the bush.

Japanese Patent Laid-Open No. 11-32162

  By the way, in the above-mentioned conventional technology, the outer cylinder of the pivot cylinder is made of forging. However, the forming operation by such forging is generally complicated, and as a result, the formation of the suspension device is complicated. It is done.

  Therefore, in order to facilitate the molding operation of the outer cylinder, it is conceivable to first cast the outer cylinder using a sand mold. However, in such a case, in order to press the bush smoothly and accurately into the outer cylinder, it is required that the inner peripheral surface of the casting surface of the cylinder is made smooth by machining. Is done. However, such machining is complicated, and therefore, it is considered that the formation of the suspension device is complicated even in the above-described manner.

  Second, it is conceivable to vacuum cast the outer cylinder using a mold. More specifically, as a mold, a mold body that can form the outer shape of the outer cylinder, and a pin mold that is a punching mold that is inserted into the mold body and can form the inner hole of the outer cylinder. Use a mold. Then, the cavity between the mold body and the pin mold is in a vacuum state, poured into the cavity and solidified, and then the pin mold is removed and the mold body is released from the mold. By casting, the outer cylinder is cast. In this way, since the inner peripheral surface of the outer cylinder has a smooth finished surface, no separate machining is required, and the molding operation of the outer cylinder is facilitated accordingly.

  However, in general vacuum casting, the following new problems arise. That is, at the time of casting, if the pin mold is entirely tapered so that the pin mold can be punched after pouring into the mold, the mold formed by the punching is formed. The inner hole of the outer cylinder is entirely tapered. Then, the outer peripheral surface of the bush that is press-fitted into the inner hole also has a tapered shape. However, in this case, the elastic characteristics in each part in the axial direction of the bush become non-uniform, and this is a pivotal cylinder having the bush. This is not preferable for pivoting the support arm.

  The present invention has been made paying attention to the above-described circumstances, and an object of the present invention is to support a support device in a vehicle so that the support arm can pivot about a pivot axis with respect to the vehicle body side. In the case where the pivot cylinder is provided with an outer cylinder that press-fits the elastic bush, the support device can be easily formed, and even in this case, the bush The elastic characteristic of each part in the axial direction is to be maintained more uniformly.

According to the first aspect of the present invention, the pivot cylinder 8 for pivotally supporting the support arm 2 so as to be pivotable about the pivot axis 6 with respect to the vehicle body 3 is rotatable about the pivot axis 6. In a vehicle support device comprising an elastic bushing 12 and an outer cylinder 13 for press-fitting the bushing 12,
The outer cylinder 13 is made of cast, and the axially intermediate portion 17 of the inner peripheral surface 15 of the outer cylinder 13 is formed in a shape substantially parallel to the pivot shaft 6, and each end 18 in the axial direction is formed. , 19 are tapered so that they can be punched in one direction A in the axial direction.

  According to a second aspect of the present invention, in addition to the first aspect of the present invention, in the free state of the pivot cylinder 8, the entire inner surface 15 of the outer cylinder 13 is substantially entirely composed of only the midway portion 17. 12 is in pressure contact with the outer peripheral surface.

  In this section, the reference numerals appended to the above terms are not intended to limit the technical scope of the present invention to the contents of the “Examples” section described later.

  The effects of the present invention are as follows.

The invention according to claim 1 is an elastic bushing in which a pivot cylinder that pivotally supports a support arm with respect to the vehicle body side so as to be pivotable about a pivot axis, and is pivotable about the pivot axis; In a support device for a vehicle including an outer cylinder for press-fitting the bush,
The outer cylinder is made of cast, and an axially middle portion of the inner peripheral surface of the outer cylinder is shaped substantially parallel to the pivot axis, and each end in the axial direction is in the axial direction. The taper shape enables die cutting in one direction.

  For this reason, when molding the outer cylinder, the outer cylinder can be easily molded by vacuum casting using a mold. More specifically, for example, as the mold, a mold main body that can form the outer shape of the outer cylinder, and a pin that is a die that is fitted into the mold main body and can form the inner hole of the outer cylinder. Use a mold. Then, the cavity between the mold and the mold body is in a vacuum state, poured into the cavity and solidified, and then the pin mold is removed so as to be extracted in the one direction, and the mold is removed. If the main body is released, the outer cylinder is formed.

  Here, as described above, the midway part of the inner peripheral surface of the outer cylinder is formed in a shape substantially parallel to the pivot axis, and attention is paid only to this midway part. It will be difficult to remove. However, since each end of the inner peripheral surface has a tapered shape that enables die cutting, if the length of each end is increased to some extent and the length of the remaining midway portion is shortened to some extent, The pin mold can be easily removed.

  And since an outer cylinder is shape | molded by casting as mentioned above, the shaping | molding can be performed easily compared with the prior art which forged the outer cylinder. Further, since the inner hole of the outer cylinder is formed by the pin mold, the inner peripheral surface of the inner hole has a smooth finished surface, and therefore no separate machining is required. As a result, the supporting device including the outer cylinder can be easily formed.

  In addition, as described above, since the middle part of the inner peripheral surface of the outer cylinder has a shape substantially parallel to the pivot axis, the bush that is press-fitted into the inner hole of the outer cylinder and press-contacts the middle part. In this portion, the elastic characteristics of the respective portions in the axial direction are held more uniformly with each other, which is preferable when the support arm is pivotally supported by the pivot cylinder having the bush.

  According to a second aspect of the present invention, in the free state of the pivot cylinder, almost all of only the midway portion of the inner circumferential surface of the outer cylinder is in pressure contact with the outer circumferential surface of the bush.

  For this reason, the portion of the outer peripheral surface of the bush that is press-fitted into the inner hole of the outer cylinder and press-contacts the inner peripheral surface of the inner hole is almost entirely in the axial direction. This is preferable because it is maintained uniformly.

  On the other hand, when the midway part of the inner peripheral surface of the outer cylinder and the midway part of the outer peripheral surface of the bush are pressed against each other with a large force due to the impact force applied from the road surface when the vehicle travels, the axial direction of the bush In addition to elastic deformation of the midway portion, each end portion of the bush is also elastically deformed, so that the impact force transmitted from the support arm side to the vehicle body side is more effectively mitigated.

  The support device for a vehicle according to the present invention includes a pivot cylinder that pivotally supports a support arm so as to be pivotable about a pivot axis with respect to the vehicle body, and the pivot cylinder is elastic. In the case where the outer cylinder for press-fitting the bush is provided, the support device can be easily molded, and even in this case, the elastic characteristics of the respective parts in the axial direction of the bush are more uniformly maintained. The best mode for carrying out the present invention in order to realize the object of the present invention is as follows.

  That is, in the support device in the vehicle, the pivot cylinder that pivotally supports the pivot arm about the pivot axis with respect to the vehicle body side includes an elastic bush that is pivotable about the pivot axis. And an outer cylinder into which the bush is press-fitted.

  The outer cylinder is made of cast, and an axially middle portion of the inner peripheral surface of the outer cylinder is shaped substantially parallel to the pivot axis, and each end in the axial direction is in the axial direction. The taper shape enables die cutting in one direction.

  In order to explain the present invention in more detail, the embodiment will be described with reference to the accompanying drawings.

  1 and 2, reference numeral 1 is a support device in a vehicle, and more specifically shows a suspension device in an automobile as an example, and an arrow Fr indicates the front in the traveling direction of the automobile.

  The support device 1 includes a support arm 2 that is a suspension arm that supports a wheel (not shown) at one end thereof, and a pivot support unit 4 that pivots the other end of the support arm 2 toward the vehicle body 3. Yes.

  The pivot means 4 includes a pivot shaft 7 which is a bolt having a pivot shaft center 6 extending in the front-rear direction and supported at both ends on the vehicle body 3 side, and an axial middle portion of the pivot shaft 7. A pivot cylinder 8 is provided that is externally fitted and pivotally supported around the pivot axis 6 with respect to the pivot axis 7 and to which the other end of the support arm 2 is fixed.

  The pivot cylinder 8 is made of a metal cylindrical inner cylinder 11 that can be relatively rotated around the pivot axis 6, and is fitted on the inner cylinder 11 to be attached to the outer peripheral surface of the inner cylinder 11. There is provided a substantially cylindrical elastic rubber bush 12 which is vulcanized and bonded, and an outer cylinder 13 which press-fits the bush 12 and integrally fixes the other end of the support arm 2.

  The support arm 2 and the outer cylinder 13 are made by vacuum casting integrally with each other. Of the inner peripheral surface 15 of the inner hole 14 in the outer cylinder 13, a midway portion 17 that is a substantially central portion in the axial direction is: The shape is substantially parallel to the pivot axis 6. Further, the end portions 18 and 19 in the axial direction of the inner peripheral surface 15 are tapered so as to enable die cutting toward the one direction A in the axial direction. The other direction B is opposite to the one direction A.

  In the above case, the lengths L1 and L2 in the axial direction of the end portions 18 and 19 are substantially the same, and the taper angles θ1 and θ2 of the end portions 18 and 19 with respect to the pivot axis 6 are also substantially the same. It is the same.

  Further, the outer peripheral surface of the midway portion 22 in the axial direction of the bush 12 has a shape substantially parallel to the pivot shaft 6 in the free state of the bush 12, that is, the midway portion 22 of the bush 12 is The axial dimension of each part is a substantially constant cylindrical shape. Further, in the free state of the pivot cylinder 8, almost the entire middle portion 17 of the inner circumferential surface 15 of the outer cylinder 13 is in pressure contact with the outer circumferential surface of the bush 12. Further, the intermediate portion 22 of the bush 12 has a trapezoidal shape in which each section in the circumferential direction has an inner peripheral surface of the intermediate portion 22 as an upper side.

  In FIG. 3, the procedure when the support arm 2 and the outer cylinder 13 are integrally vacuum cast using the mold 24 will be described.

  The mold 24 is a mold body 25 that can form the outer shape of the support arm 2 and the outer cylinder 13, and a die that can be fitted into the mold body 25 and can form the inner hole 14 of the outer cylinder 13. A pin mold 26 is provided, and a cavity is formed between the mold 24 and the mold body 25. After the molten metal is poured into the cavity in a vacuum state and solidified, the pin mold 26 is removed so as to be extracted in the one direction A, and the mold body 25 is released. 2 and the outer cylinder 13 are integrally cast.

  According to the above configuration, the outer cylinder 13 is made of cast, and the axially intermediate portion 17 of the inner peripheral surface 15 of the outer cylinder 13 is formed in a shape substantially parallel to the pivot shaft 6, and the axial direction Each of the end portions 18 and 19 has a tapered shape that enables die cutting in one direction A in the axial direction.

  For this reason, when molding the outer cylinder 13, the outer cylinder 13 can be easily molded by vacuum casting using the mold 24. More specifically, for example, as the mold 24, a mold main body 25 that can form the outer shape of the outer cylinder 13, and an inner hole 14 of the outer cylinder 13 that can be fitted into the mold main body 25 can be formed. A pin die 26 that is a punching die to be used is used. Then, the cavity between the mold 24 and the mold body 25 is in a vacuum state, poured into the vacuum cavity and solidified, and then the pin mold 26 is removed so as to be extracted in the one direction A. When the mold body 25 is released, the outer cylinder 13 is formed.

  Here, as described above, the midway portion 17 of the inner peripheral surface 15 of the outer cylinder 13 is formed in a shape substantially parallel to the pivot axis 6. It is considered that it is difficult to remove the pin mold 26. However, since the end portions 18 and 19 of the inner peripheral surface 15 have a tapered shape that enables die cutting, the lengths L1 and L2 of the end portions 18 and 19 are increased to some extent, and the remaining halfway portions. If the length L3 of 17 is shortened to some extent, the pin die 26 can be easily removed.

  And since the outer cylinder 13 is shape | molded by casting as mentioned above, the shaping | molding can be performed easily compared with the prior art which forged the outer cylinder. Further, since the inner hole 14 of the outer cylinder 13 is formed by the pin mold 26, the inner peripheral surface of the inner hole 14 has a smooth finish surface, so that no separate machining is required. The outer cylinder 13 can be formed more easily. As a result, the support device 1 including the outer cylinder 13 can be formed easily.

  Further, as described above, the midway portion 17 of the inner peripheral surface 15 of the outer cylinder 13 has a shape substantially parallel to the pivot shaft 6, so that it is press-fitted into the inner hole 14 of the outer cylinder 13 and the middle The portion of the bush 12 that is in pressure contact with the portion 17 maintains the elastic characteristics of the respective portions in the axial direction more uniformly. This is because the support arm 2 is pivotally supported by the pivot cylinder 8 having the bush 12. This is preferable.

  Further, as described above, in the free state of the pivot cylinder 8, only the middle portion 17 of the inner peripheral surface 15 of the outer cylinder 13 is in pressure contact with the outer peripheral surface of the bush 12. Yes.

  For this reason, the portion of the outer peripheral surface of the bush 12 that is press-fitted into the inner peripheral surface 15 of the inner hole 14 of the outer cylinder 13 and press-contacts the inner hole 14 is substantially elastic over the entire axial direction. It is preferable that the characteristics are more uniformly maintained.

  On the other hand, when the midway portion 17 of the inner peripheral surface 15 of the outer cylinder 13 and the midway portion 22 of the outer peripheral surface of the bush 12 are pressed against each other with a large force due to an impact force applied from the traveling road surface during traveling of the vehicle, In addition to the elastic deformation of the midway portion 22 in the axial direction of the bush 12, each end portion of the bush 12 is also elastically deformed, so that an impact force that is transmitted from the support arm 2 side to the vehicle body 3 side is further increased. Is effectively mitigated.

  Although the above is based on the illustrated example, the support device 1 is not limited to the one having the support arm 2 for supporting the wheel with respect to the vehicle body 3 described above. A support arm 2 that is a torque rod that elastically supports the engine unit may be provided.

  Further, the support arm 2 and the vehicle body 3 may be provided opposite to each other with respect to the pivot support means 4. Further, the midway part 17 of the inner peripheral surface 15 of the outer cylinder 13 may be completely parallel to the pivot axis 6, but the midway part 17 is tapered in the other direction B. In addition, the taper angle may be made extremely smaller than the taper angles θ1 and θ2 of the end portions 18 and 19. In this way, the pin mold 26 can be easily removed, that is, the outer cylinder 13 can be easily formed. Even in this case, the portion of the bush 12 that is press-fitted into the inner hole 14 of the outer cylinder 13 and press-contacted with the midway portion 17 maintains the elastic characteristics of the respective portions in the axial direction substantially uniformly. preferable.

It is a partial top view of a support device. It is 2-2 arrow sectional drawing of a support apparatus. It is plane sectional drawing which shows the casting procedure of an outer cylinder.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Support apparatus 2 Support arm 3 Car body 4 Pivot support means 6 Pivot support center 7 Pivot support shaft 8 Pivot support cylinder 11 Inner cylinder 12 Bush 13 Outer cylinder 14 Inner hole 15 Inner peripheral surface 17 Midway part 18 End part 19 End part 22 Middle part 24 Mold 25 Mold body 26 Pin mold A One direction B Other direction θ1, θ2 Taper angle L1, L2, L3 Length

Claims (2)

An elastic bush for pivotally supporting the support arm with respect to the vehicle body so as to be pivotable about a pivot axis, and an outer cylinder for press-fitting the bush. In a support device for a vehicle comprising:
The outer cylinder is made of cast, and an axially middle portion of the inner peripheral surface of the outer cylinder is shaped substantially parallel to the pivot axis, and each end in the axial direction is in the axial direction. A support device for a vehicle, wherein the support device has a tapered shape that enables die cutting in one direction.   2. The apparatus according to claim 1, wherein, in the free state of the pivot cylinder, substantially all of only the midway portion of the inner circumferential surface of the outer cylinder is in pressure contact with the outer circumferential surface of the bush. Support device in a vehicle.

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