JP2009018707A - Cab mount structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cab mount structure easy to perform tilt-lock without hindering the vibration shut-out performance. <P>SOLUTION: Rubber bush mechanisms 16 and 16 for shutting out vibration respectively has a rubber bush press-in portion 18 and a rubber bush 19 housed in the rubber bush press-in portion 18. The rubber bush 19 is formed of an outer cylinder 19a, an inner cylinder 19b and an elastic body 19c pinched between the outer cylinder 19a and the inner cylinder 19b, and a plurality of stoppers 30 are provided between the outer cylinder 19a and the inner cylinder 19b. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a cab mount structure. More specifically, a tilt cylinder having one end fixed to the chassis frame side and the other end fixed to the cab main member side, and a front cab mount to make the cab capable of tilting the lorry detachable from the chassis frame. And a rear cab mount, and a front cab mount having a rubber bushing mechanism for vibration isolation via a mounting bracket.

  Many cab-over type trucks have a structure in which the entire cab is tilted (inclined forward) in order to inspect or repair the engine and its surroundings. FIG. 7 is a simplified diagram of such a vehicle. In FIG. 7, the left side is described as the front and the right side is described as the rear.

In FIG. 7, a tilt hinge 5 is provided at the front end of the chassis frame 4. The cab 2 is fixed to the chassis frame 4 so as to be rotatable about the tilt hinge 5 as a pivot.
In FIG. 7, reference numeral 8 denotes a tilt cylinder for tilting the cab 2. Reference numeral 2 c is a tilt lock device provided at the rear end of the cab 2.

  The tilt lock device 2 c is adapted to engage with the rear cab mount 12. In the tilt lock device 2c, the engagement is not released except when the cab 2 is tilted.

FIG. 8 shows a mechanism for mounting the cab 2 on the chassis frame 4.
In FIG. 8, the cab 2 indicated by an imaginary line (one-dot chain line) is fixed to the cab main member 6.
The front part of the cab main member 6 is fixed to the upper part of the bracket 15. The rear part of the cab main member 6 is engaged with the upper part of the rear cab mount 12 by the tilt lock device 2c.
Further description will be given with reference to FIG. 9 showing the front cab mount 10.

8 and 9, the lower part of the bracket 15 is rotatably supported by the arm 14 of the cab suspension link 13 via a rubber bushing mechanism 16A. FIG. 10 shows the cab suspension link 13.
Referring again to FIG. 9, rubber bushing mechanisms 16 </ b> A are attached to the front portion and the rear portion of the arm 14 of the cab suspension link 13.
The rubber bush mechanism 16A will be described later with reference to FIGS.

In FIG. 9, the front part of the arm 14 is rotatably fixed to the upper part of the hinge bracket 17 via a rubber bushing mechanism 16A.
The lower part of the hinge bracket 17 is fixed to the chassis frame 4.

  In FIG. 9, an air spring 27 is disposed between the front upper portion of the arm 14 and the front lower portion of the bracket 15. A shock absorber 28 is disposed between the front part of the arm 14 and the front part of the bracket 15.

  In FIG. 8, the upper portion of the tilt cylinder 8 is rotatably attached to the lower end portion of the cab main member 6. Further, the lower portion of the tilt cylinder 8 is rotatably attached to the chassis frame 4.

FIG. 11 is an X arrow view of the rear cab mount 12 shown in FIG.
In FIG. 12, a tilt lock device 2 c is provided below the cab 2. The tilt lock device 2c is configured to engage with the lock pin 12p. However, in FIG. 11, the tilt lock device 2c and the lock pin 12p are not engaged.
The lock pin 12p is fixed to the member 40. The member 40 is provided on the chassis frame 6 so as to be movable up and down. An air spring 39 is disposed between the member 40 and the chassis frame 4.

With the above configuration, the chassis frame 4 and the cab main member 6 are coupled to each other via the four rubber bush mechanisms 16A.
Further, the cab 2 is elastically suspended from the chassis frame 4 by the front air spring 27 and the shack absorber 28 and the rear air spring 39.

12 and 13 show a conventional rubber bush mechanism 16A.
In FIG. 12 as viewed from the arrow X1 in FIG. 9, a rubber bush mechanism 16A is attached to the bracket 15 or 17.
The rubber bush mechanism 16 </ b> A includes a rubber bush press-fit portion 18, a rubber bush 19, and a cushion 20.
In FIG. 12, reference numeral 23 indicates a pin, and the pin 23 is a member for attaching the rubber bush mechanism 16 </ b> A to the bracket 15 or 17.

As shown in FIG. 13, the rubber bush 19 includes an outer cylinder 19a, an inner cylinder 19b, and a cylindrical elastic body 19c. The elastic body 19c is located between the outer cylinder 19a and the inner cylinder 19b. It is glued to.
In order to connect the cab 2 and the chassis frame 4, the elastic body 19 c needs to be hardened to some extent (high spring constant). However, softer (lower spring constant) is preferable for flexibility and vibration isolation.
In the rubber bush 19, the outer cylinder 19 a is press-fitted into the rubber bush press-fit portion 18.

The cushion 20 is configured by attaching an elastic material (not shown) to a disk-shaped metal seat plate. The cushion 20 is fixed to the inner cylinder 19b.
A pin 23 is inserted into the inner cylinder 19 b of the rubber bush 19 and attached to the bracket 15 or 17.

  The rubber bush mechanism 16A having the above configuration softly supports the front / rear, left / right and vertical forces applied from the chassis frame 6 to the cab 2 by the elasticity of the elastic body 19c. Moreover, the elastic material of the cushion 20 has the effect | action which suppresses the interference sound of the rubber bush press-fit part 8 and the cushion 20 during operation.

Such problems in the conventional rubber bushing mechanism 16A will be described mainly with reference to FIG.
In FIG. 11, the chevron-shaped guide notch 2d of the tilt lock device 2c is shifted left and right by δ from the core of the pin 12p.
This deviation δ occurs when the tilt cylinder 8 starts tilting work.

In the thrust of the tilt cylinder 8, in particular, the horizontal component force F (see FIG. 8) deforms the elastic body 19c of the rubber bush mechanism 16A.
The vertical component force in the thrust of the tilt cylinder 8 does not act to change the horizontal position of the chassis frame 4 and the cab 2 and can be ignored.

The thrust of the tilt cylinder 8 directly acts only on the left cab main member 6. As a result, the rigidity of the cab suspension link 13 is also affected, and the deformation of the elastic body 19c of the left rubber bush mechanism 16A becomes larger than the deformation of the right elastic body 19c. And the position of the cab 2 and the chassis frame 6 shift | deviates and the cab 2 twists.
The positional deviation between the cab 2 and the chassis frame 6 is greatest at the rear. As a result, as shown in FIG. 11, a left-right deviation δ of the tilt lock device 2c occurs.
Due to the presence of the deviation δ, tilt lock becomes difficult when the tilted cab 2 is returned to the normal horizontal position.

In the prior art relating to a freight vehicle adopting a structure in which the tilt cab is tilted by one cylinder 8, a technique for solving the above-described problems has not been proposed yet.
As another conventional technique, a technique for suppressing the deformation of the rubber bush of the suspension has been proposed (see Patent Document 1). However, the related art (Patent Document 1) is a technique related to a rubber bush for air suspension, and does not solve the above-described problems.
Further, there is a conventional technique related to the structure of the rubber bush (see Patent Document 2). However, this technique (Patent Document 2) is a technique for connecting the rubber bushes and does not solve the above-described problem.
Japanese Patent Laid-Open No. 7-1342 Japanese Utility Model Publication No. 63-101341

  The present invention has been proposed in view of the above-described problems of the prior art, and is a cab mount structure that allows a tiltable cab of a lorry to be attached to and detached from a chassis frame, and impairs vibration isolation. The object is to provide a cab mount structure that can be easily tilt-locked.

  The cab mount structure according to the present invention has one end fixed to the chassis frame (4) side and the other end (to make the cab (2) tiltable for a lorry be detachable from the chassis frame (4)). A tilt cylinder (8) fixed to the cab main member (6) side, a front cab mount (10) and a rear cab mount (12) are provided, and the front cab mount (10) is vibrated via a mounting bracket (15). In the cab mount structure provided with the rubber bushing mechanism (16) for blocking, the rubber bush mechanism (16) for blocking vibration is housed in the rubber bush press-fitting part (18) and the rubber bush press-fitting part (18). The rubber bush (19) includes an outer cylinder (19a), an inner cylinder (19b), an outer cylinder (19a), and an inner cylinder (19a). And an elastic body (19c) sandwiched between (19b), and a plurality of stoppers (30) for suppressing relative displacement between the outer cylinder (19a) and the inner cylinder (19b) are provided. (Claim 1).

  The stopper (30) does not suppress the deformation of the rubber bush (19) if the deformation amount of the rubber bush (19) is less than a predetermined value, but if the deformation amount of the rubber bush (19) exceeds a predetermined value, the rubber bush (19). It is preferable to be configured to suppress the deformation of (19) (Claim 2).

The stopper (30) protrudes radially outward from the outer peripheral surface of the inner cylinder (19b), and includes a top portion (30a) of the stopper and an inner peripheral surface (19i) of the outer cylinder (19a). Is preferably 4 mm or less (Claim 3).

  The stopper (36) protrudes radially inward from the inner peripheral surface (19J) of the outer cylinder (19A), and includes a top (36a) of the stopper and an outer peripheral surface (19o) of the inner cylinder (19b). Is preferably 4 mm or less (claim 4).

  The stopper (36) is preferably formed by bending an outer cylinder (19A) (Claim 5).

  According to the present invention having the above-described configuration, the rubber bush (19) housed in the rubber bush press-fitting portion (18) reduces vertical, front-rear and left-right vibrations input from the chassis frame (4). Further, excessive vertical and longitudinal deformation of the rubber bush (19) due to the thrust of the tilt cylinder (8) is suppressed by the stopper (30), so that it is difficult to tilt lock due to twisting of the cab (2) which has occurred conventionally. It will be resolved.

  In the present invention, if the amount of deformation of the rubber bush (19), which is a relative displacement between the outer cylinder (19a) and the inner cylinder (19b), is less than a predetermined value, the deformation of the rubber bush pressure (19) is not suppressed, and the rubber If the stopper (30) is configured to suppress the deformation of the rubber bush (19) when the amount of deformation of the bush exceeds a predetermined value (Claim 2), the rubber bush (19) at the time of tilt lock is excessively large. The situation where the deformation can be suppressed and the tilt lock becomes difficult is solved. At the same time, since excessive deformation of the rubber bush (19) can be suppressed, the rigidity (spring constant) of the rubber bush (19) can be lowered to improve vibration isolation during operation.

Further, according to the present invention, since the stopper (30) can be incorporated in the rubber bush (19), the management of the parts becomes easy.
And according to this invention, it becomes possible to provide the rubber bush (39) which can be manufactured easily and can aim at weight reduction.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
The cab mount structure of the present invention is characterized by a rubber bush mechanism. Except for the rubber bush mechanism, the configuration is the same as the conventional configuration shown in FIGS.
Therefore, in the illustrated embodiment, the rubber bush will be mainly described.

First, a first embodiment of the present invention will be described with reference to FIGS.
1 to 3, members similar to those described in FIGS. 12 and 13 are given the same reference numerals and names.

  A rubber bush mechanism 16 is attached to a bracket 15 or 17 in FIG.

The rubber bush mechanism 16 includes a cylindrical rubber bush press-fit portion 18, a rubber bush 19, and a cushion 20.
In FIG. 1, reference numeral 23 denotes a pin for attaching the rubber bush mechanism 16 to the bracket 15 or 17.

2 and 3, the rubber bush 19 is formed of an outer cylinder 19a, an inner cylinder 19b, and an elastic body 19c bonded between the outer cylinder 19a and the inner cylinder 19b.
As described above, the elastic body 19 c needs to be hardened to some extent in order to connect the cab 2 and the chassis frame 4. However, softer (lower spring constant) is preferable for flexibility and vibration isolation.
In the rubber bush 19, the outer cylinder 19 a is press-fitted into the rubber bush press-fit portion 18.

The elastic body 19c of the rubber bush 19 is bonded to the outer cylinder 19a. As shown in FIG. 2, four gaps 19S are formed in the elastic body 19c at equal intervals in the circumferential direction.
In other words, the outer cylinder 19a and the inner cylinder 19b are coupled by the elastic body 19c having the gap 19S.

Four stoppers 30 are provided on the outer peripheral surface 19o of the inner cylinder 19b at equal intervals in the circumferential direction. The four stoppers 30 project radially outward in the radial direction.
The stopper 30 extends in the radial direction in the gap 19S. The distance α between the top portion (radially outer end portion) 30a of the stopper 30 and the inner peripheral surface 19i of the outer cylinder 19a is set to be 4 mm or less.

The distance α (for example, 4 mm) is set as a dimension such that the deformation of the rubber bush 19 does not hinder the tilt lock.
Further, the distance α (for example, 4 mm) is a distance within the range of elastic deformation during normal operation after tilt lock, and is a distance for vibration isolation.

The cushion 20 is configured by adhering a circular elastic body (not shown) to a disc-shaped metal seat plate.
The cushion 20 is fixed in opposite directions to both end portions of the inner cylinder 19b.
The cushion 20 has a slightly larger diameter than the bush press-fit portion 18.
Between the cushion 20 and the side end portion 18e of the rubber bush press-fitting portion 18, the cushion 20 is disposed so as to have an appropriate distance.

  A pin 23 is inserted into the inner cylinder 19 b of the rubber bush 19. The rubber bush mechanism 16 is attached to the bracket 15 or 17 by the pin 23.

The operation of the rubber bush mechanism 16 will be described.
When the cab 2 is tilted, the rubber bush mechanism 16 receives a horizontal component force F (see FIG. 9) in the forward direction of the tilt cylinder 8.
Due to the horizontal component force F, the elastic body 19c of the rubber bush 19 is deformed (bent).
The bending in the elastic body 19c is a relative displacement between the outer cylinder 19a and the inner cylinder 19b, and is determined by the spring constant of the elastic body 19c.

However, with respect to the excessive horizontal component force F of the tilt cylinder 8 applied only during tilting, the stopper 30 abuts (or interferes) with the inner peripheral surface 19i of the outer cylinder 19a, so that the elastic body of the rubber bush 19 The deformation amount or bending of 19c is suppressed.
In the first embodiment, the radial deflection is such that the distance (distance α = 4 mm) between the top 30 a of the stopper 30 and the inner peripheral surface 19 i of the stopper 30 is the upper limit value of the deformation amount or the deflection of the elastic body 19 c of the rubber bush 19. It is. In other words, the deformation amount or the bending of the elastic body 19c of the rubber bush 19 is suppressed so that the upper limit value is the distance α (= 4 mm).
If the deflection of the elastic body 19c is 4 mm, the tilt lock device 2c is practically engaged with the lock pin 12p (see FIG. 11). Therefore, there is no problem in tilt lock work.

Since the deflection (deformation amount) of the elastic body 19c due to an excessive load at the time of tilt lock is suppressed by the contact (interference) between the top 30a of the stopper 30 and the inner peripheral surface 19i of the outer cylinder, the elastic body 19c of the rubber bush 19 It is possible to improve the vibration isolation in normal operation by setting a low spring multiplier.
Here, during normal operation, the deflection (deformation amount) of the elastic body 19c hardly exceeds 4 mm. Accordingly, the contact (interference) between the top 30a of the stopper 30 and the outer peripheral surface 19i of the outer cylinder does not adversely affect the riding comfort during normal operation.

As described above, the deflection of the elastic body 19c due to excessive force during tilting is suppressed by the stopper 30. Then, the tilt lock problem is solved.
Further, since the elastic body 19c can be selected to have an arbitrary spring constant (low spring multiplier), vibration isolation in normal operation is improved.

Next, a second embodiment of the present invention will be described with reference to FIGS.
4 to 6, different parts from the first embodiment of FIGS. 1 to 3 will be mainly described.

4 to 6, the rubber bush mechanism 16B includes a rubber bush press-fitting portion 18, a rubber bush 39, and a cushion 20.
In FIG. 4 as viewed in the direction of arrow X1 in FIG. 9, a rubber bush mechanism 16B is attached to the bracket 15 or 17.

The rubber bush mechanism 16 </ b> B includes a cylindrical rubber bush press-fitting portion 18, a rubber bush 39, and a cushion 20.
In FIG. 4, reference numeral 23 denotes a pin, and the rubber bush mechanism 16 </ b> B is attached to the bracket 15 or 17 by the pin 23.

5 and 6, the rubber bush 39 is formed of an outer cylinder 19A, an inner cylinder 19b, and an elastic body 19C bonded between the outer cylinder 19A and the inner cylinder 19b.
The elastic body 19C is bonded to the inner peripheral surface 19J of the outer cylinder 19A.

A stopper 36 is formed by bending the outer cylinder 19A inward in the radial direction. The stopper 36 protrudes in a triangular mountain shape inward in the radial direction.
In the second embodiment, four stoppers 36 are formed at equal intervals in the circumferential direction, and a gap 19 s is formed on the outer side in the radial direction of the stopper 36.

The top part (radially inner end part) 36a of the stopper 36 is arranged so that the distance β between the outer peripheral surface 19o of the inner cylinder 19b is 4 mm or less.
The distance β (in the second embodiment, β = 4 mm) between the top portion (radially inner end portion) 36a of the stopper 36 and the inner cylinder outer peripheral surface 19o is such that deformation of the rubber bush 39 hinders tilt lock. There are no dimensions.
The distance β (= 4 mm) is set to a value that can absorb the amount of elastic deformation (deflection) for vibration isolation during normal operation after tilt lock.

The operation of the rubber bush mechanism 16B will be described.
When the cab 2 is tilted, the rubber bush mechanism 16B receives a horizontal component force F (see FIG. 8) in the forward direction of the tilt cylinder 8.
Due to the horizontal component force F, the elastic body 19C of the rubber bush 39 is deformed (bent).
The deflection of the elastic body 19C is a relative displacement between the outer cylinder 19A and the inner cylinder 19b, and is determined by the spring constant of the elastic body 19C.

However, with respect to the excessive horizontal component force F of the tilt cylinder 8 that is applied only during tilting, the stopper 36 abuts (interferences) with the outer peripheral surface 19o of the inner cylinder 19b, so that further deformation or deflection is limited. Is done. That is, in the second embodiment shown in FIGS. 4 to 6, the deflection or deformation in the radial direction in FIG. 5 is suppressed to the distance β (= 4 mm) between the top 30a of the stopper 36 and the inner cylinder outer peripheral surface 19o. .
If the deflection of the elastic body 19C is 4 mm, the tilt lock device 2c is practically engaged with the lock pin 12p (see FIG. 11). Therefore, there is no problem in tilt lock work.

With respect to the excessive horizontal component force F of the tilt cylinder 8 applied only when tilting, the top portion 30a of the stopper 36 abuts (interferences) with the outer peripheral surface 19o of the inner cylinder, so that further deformation is limited. The spring constant of the elastic body 19C can be lowered to improve the vibration isolation in normal operation.
In the normal operation, the amount of deformation of the elastic body 19C is within the above-mentioned distance β (= 4 mm). Therefore, the top 30a of the stopper 36 and the inner cylinder outer peripheral surface 19o interfere with each other due to the vibration in the normal operation. There is no negative impact on ride comfort.

  Also in the second embodiment, the deflection (deformation amount) of the elastic body 19C due to an excessive force at the time of tilting is limited, and the tilt problem is solved. In addition, since the elastic body 19C can be selected to have an arbitrary (low) spring constant, vibration isolation in normal operation is improved.

  Other configurations and operational effects in the second embodiment of FIGS. 4 to 6 are the same as those of the first embodiment of FIGS.

It should be noted that the illustrated embodiment is merely an example, and is not a description to limit the technical scope of the present invention.
For example, in the rubber bush mechanisms 16, 16B, the stoppers 30, 36 are arranged at equal intervals in the circumferential direction. However, the arrangement of the stoppers 30 and 36 can be set at unequal intervals in the circumferential direction in consideration of the force applied to the rubber bush mechanisms 16 and 16B.

The external view of the rubber bush mechanism with which 1st Embodiment of this invention is mounted | worn. The front view of the rubber bush mechanism of FIG. FIG. 2 is a side sectional view of the rubber bush mechanism of FIG. 1. The external view of the rubber bush mechanism with which 2nd Embodiment is mounted | worn. The front view of the rubber bush mechanism of FIG. The sectional side view of the 4th rubber bush mechanism. The figure which shows the freight vehicle and mounting site | part with which this invention is mounted | worn. The detailed side view of the site | part with which this invention is mounted | worn. The detailed perspective view of the member with which this invention is mounted | worn. The detailed perspective view of the site | part with which this invention is mounted | worn. The figure for demonstrating the conventional subject. The external view of the conventional rubber bush mechanism. FIG. 13 is a side sectional view of FIG. 12.

Explanation of symbols

2 .... Cabin 4 ... Chassis frame 5 ... Tilt hinge 6 ... Cabin main member 8 ... Tilt cylinder 10 ... Front cab mount 12 ... Rear cab mount 13 ... Cab suspension link 14 ... Arm 15 ... Mounting bracket 16 ... Rubber bushing mechanism 17 ... · Hinge bracket 18 ··· Rubber bush press-fit portion 18i · · · inner diameter 19, 39 · · · rubber bush 19a, 19A · · · outer cylinder 19b · · · · · · inner cylinder 20 ... Cushion 23 ... Pin 27 ... Air springs 30, 36 ... Stopper

Claims (5)

Rubber bushing mechanism for vibration isolation via a mounting bracket on the front cab mount with a tilt cylinder with one end fixed to the chassis frame and the other end fixed to the cab main member side, and a front cab mount and rear cab mount The rubber bushing mechanism for vibration isolation includes a rubber bush press-fit portion and a rubber bush accommodated in the rubber bush press-fit portion, and the rubber bush includes an outer tube, an inner tube, and a rubber bush press-fit portion. A cab mount structure comprising an elastic body sandwiched between an outer cylinder and an inner cylinder and provided with a plurality of stoppers for suppressing relative displacement between the outer cylinder and the inner cylinder. The stopper is configured not to suppress the deformation of the rubber bush if the deformation amount of the rubber bush is less than a predetermined value, but to suppress the deformation of the rubber bush if the deformation amount of the rubber bush exceeds a predetermined value. The cab mount structure according to Item 1. The stopper is projected radially outward from the outer peripheral surface of the inner cylinder, and the distance between the top of the stopper and the inner peripheral surface of the outer cylinder is 4 mm or less. Cab mount structure. The cab mount according to claim 1, wherein the stopper protrudes radially inward from the inner peripheral surface of the outer cylinder, and the distance between the top of the stopper and the outer peripheral surface of the inner cylinder is 4 mm or less. Construction. The cab mount structure according to claim 4, wherein the stopper is formed by bending an outer cylinder.

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