JP4337566B2 - Fixing device for lift cylinder for forklift - Google Patents

Description

  The present invention relates to a lift cylinder fixing device for raising and lowering a mast of a forklift.

  As a fixing device for a lift cylinder for a forklift, those described in Patent Document 1 or Patent Document 2 have been proposed. In the fixing device described in Patent Document 1, a bracket 35 is attached to a side edge of the outer mast 12 as shown in FIG. 9 showing a plane cross section, and the screw shaft portion 37 is passed through the bracket 35 via an elastic body 36. A horizontal U-shaped holding portion 38 is connected to a flange portion 37 a that is supported and connected to the tip of the screw shaft portion 37. The holding portion 38 is fitted to the outer peripheral surface of the cylinder main body 18A of the lift cylinder 18 and a clamp 39 bridged at both ends of the holding portion 38 is screwed into a male screw portion 38a formed in the holding portion 38. The lift cylinder 18 is tightened to connect the lift cylinder 18 to the outer mast 12.

  On the other hand, the fixing device described in Patent Document 2 is a nut that penetrates a support bolt 41 through a bracket 35 attached to the outer mast 12 and is screwed to the support bolt 41 as shown in FIG. The support bolt 41 is fixed to the bracket 35 by 42 and 43. On the other hand, the front end portion of the support bolt 41 with the nuts 42 and 43 loosened with respect to the locking screw hole 45 formed on the outer peripheral surface of the cap 44 fitted to the upper end portion of the cylinder body 18A of the lift cylinder 18. And the lift cylinder 18 is connected to the outer mast 12, and the cap 44 is prevented from rotating with respect to the cylinder body 18A.

Also, as shown in FIG. 11, a small-diameter stepped portion 46 is formed above the outer peripheral surface of the cap 44 of the lift cylinder 18, and a connecting ring 47 connected to the bracket 35 on the outer mast 12 side with respect to the stepped portion 46 is provided. A fixing device for a lift cylinder adapted to be fitted is also proposed.
JP 61-226497 A JP-A-8-91791

  However, since the lift cylinder fixing device described in Patent Document 1 simply holds the outer peripheral surface of the lift cylinder 18 by the holding portion 38 and the clamp 39, the following measures are required. That is, with respect to the lower end portion of the lift cylinder 18, as shown in FIG. 12, the lift is lifted with respect to the fitting hole 14 a provided in the mast support 14 that connects the lower end portions of the pair of left and right outer masts 12 (only one is shown). The fitting convex part 21 provided in the lower end part of the cylinder 18 is fitted, and the attachment position of the lift cylinder 18 is set. In order to prevent the lift cylinder 18 from rotating on the mast support 14, an introduction groove 14b and a locking groove 14c are formed in the mast support 14, and the locking groove 14c is provided on the lower end surface of the lift cylinder 18. The rotation prevention pin 51 has to be introduced and locked from the introduction groove 14b, and there is a problem that a part dedicated to the rotation prevention of the lift cylinder 18 is required separately. Further, in order to prevent the fitting convex portion 21 of the lift cylinder 18 from coming out upward from the fitting hole 14a of the mast support 14, a screw hole 21a is formed in the lower end surface of the fitting convex portion 21, and this screw hole It is necessary to bring the washer 53 into contact with the lower surface of the mast support 14 by a retaining bolt 52 that is screwed into 21a. For this reason, there is a need for a dedicated part for preventing the slipping, which increases the number of parts, making the manufacturing and assembling work cumbersome and making it impossible to reduce the cost.

  On the other hand, in the lift cylinder fixing device of Patent Document 2, the support bolt 41 is screwed into the rotation screw hole 45 provided in the cap 44, so that the fitting convex portion 21 of the lift cylinder 18 is prevented from coming off. There is no need to provide a separate prevention structure. However, the support bolt 41 exhibits the function of stopping the rotation of the cylinder body 18A and the cap 44, but does not have the function of stopping the mast support 14 and the cylinder body 18A. The pin 51 cannot be omitted. Moreover, since it is necessary to form the rotation screw hole 45 in the cap 44, there also exists a problem that processing is troublesome. Further, since the stop screw hole 45 is formed in the cap 44, the outer diameter and length of the cap 44 are restricted, and it is difficult to form the stop screw hole 45 in the cylinder body 18A. There was a problem that there were restrictions on the types of lift cylinders that could be applied.

  Further, the above-described parts for preventing the removal are not necessary for the fixing device for the lift cylinder 18 in which the step portion 46 is provided in the cap 44 shown in FIG. However, since the rotation structure of the lift cylinder 18 is required, and the troublesome work of processing the stepped portion 46 on the cap 44 is also required, and the stepped portion 46 is formed on the cap 44. There was also a problem that there were restrictions.

  The first object of the present invention is to eliminate the above-mentioned problems in the prior art, eliminate the dedicated parts for preventing the lift cylinder from coming off, simplify the structure, and easily perform the manufacturing and assembling operations. It is an object of the present invention to provide a fixing device for a lift cylinder for a forklift that can reduce the cost and relax the restrictions on the applicable lift cylinder model.

  The second object of the present invention is to reduce the cost by simplifying the structure, facilitating the manufacturing and assembling work by eliminating the dedicated parts for preventing the rotation of the lift cylinder in addition to the first object. An object of the present invention is to provide a lift cylinder fixing device for a forklift that can be realized.

In order to solve the above problems, the invention according to claim 1 is a lift cylinder fixing device in which a supporter for supporting a lift cylinder is attached to a bracket provided on an outer mast. Protrusions projecting sideways are provided on the surface, and the projecting parts are overflow pipes or air vent plugs provided in advance in the lift cylinder, and engage the projecting parts with the supporter, The gist of the present invention is to provide an engaging recess for preventing movement and turning.

The gist of the invention according to claim 2 is that, in claim 1, the protrusion is provided on a cylinder body of a lift cylinder .

A third aspect of the present invention is summarized in that, in the first or second aspect , the supporter includes a supporter body and a buffer member, and the engaging recess is formed in the buffer member.

According to a fourth aspect of the present invention, in the third aspect , the supporter main body is formed in a notched cylindrical body that is fitted to the outer peripheral surface of the lift cylinder, and is bifurcated at both ends of the body. A gist of the invention is that the arm portion is connected to the bracket by connecting means.

According to a fifth aspect of the present invention, in the fourth aspect , the shock-absorbing member is interposed between the pair of arm portions, and the protrusion on the inner surface of the shock-absorbing member that contacts the outer peripheral surface of the lift cylinder. The gist of the present invention is that a joint recess is provided, and a stopper is provided on both the left and right sides of the lower end of the buffer member to be locked to the lower end edge of the arm portion to prevent the buffer member from moving upward. .

According to a sixth aspect of the present invention, in the fourth or fifth aspect , the bracket is provided with a spacer interposed between a pair of arm portions of the supporter body, and the connecting means is disposed in a through hole of the spacer. As a gist, the connecting bolt or the connecting pin is penetrated.

According to the first aspect of the present invention, the protrusion of the lift cylinder is engaged with the engagement recess provided in the supporter, and the upward movement of the lift cylinder is prevented. For this reason, it is not necessary to separately provide a part for preventing the slipping off at the lower end portion of the lift cylinder, and the number of parts can be reduced to facilitate the manufacturing and assembling work, thereby reducing the cost. Further, since the protrusion is provided on the lift cylinder, the restrictions on the applicable lift cylinder model can be relaxed as compared with the conventional structure in which the rotation screw hole is formed in the cap. Further, since the protrusion is an overflow pipe or an air vent plug, it is not necessary to newly process a dedicated protrusion for the lift cylinder, and the cost can be further reduced.

  In addition to the effect of the invention described in claim 1, the invention described in claim 2 prevents the lift cylinder from rotating because the projection is provided on the cylinder body of the lift cylinder, and the lower end of the lift cylinder. It is not necessary to provide a dedicated rotation prevention component, and the number of components can be reduced to facilitate manufacturing and assembling operations, thereby reducing costs.

According to a third aspect of the invention, in addition to the effect of the invention according to claim 1 or 2, since the engaging recess is formed on the buffer member, relaxation of vibration of the mast is transmitted to the protrusion Thus, damage due to fatigue of the protrusion can be prevented.

In addition to the effect of the invention described in claim 3 , the invention described in claim 4 can easily perform the work of attaching / detaching the supporter to / from the lift cylinder, and can hold the buffer member between the pair of arm portions. it can.

According to the fifth aspect of the invention, in addition to the effect of the fourth aspect of the invention, a buffer material can be easily incorporated between the pair of arm portions without using a dedicated connector.
According to the sixth aspect of the invention, in addition to the effect of the fourth or fifth aspect , the arm portion of the supporter body can be stably attached to the bracket.

Hereinafter, an embodiment of a fixing device for a lift cylinder for a forklift that embodies the present invention will be described with reference to FIGS.
FIG. 1 is a front view of the mast assembly 11 as viewed from the rear of the forklift, and FIG. 2 is a plan view of the mast assembly 11. As shown in FIG. 1, the upper and lower ends of the pair of left and right outer masts 12 are connected in parallel to each other by upper and lower mast supports 13 and 14. A pair of left and right inner masts 15 and 15 are installed inside the outer masts 12 and 12 in parallel, and upper ends of the inner masts 15 and 15 are connected by upper and lower mast supports 16 and 17.

  A pair of left and right lift cylinders 18 and 18 are erected in parallel with each other on the upper surface of the mast support 14 so as to be close to the outer masts 12 and 12. Piston rods 19, 19 of both lift cylinders 18, 18 are connected to both ends of the mast support 16. The inner masts 15 and 15 are moved up and down via the mast support 16 by the movement of the piston rods 19 and 19 in the vertical direction. In addition, although not shown in figure, the fork is attached to the inner masts 15 and 15 via a lift bracket.

  The upper portions of the lift cylinders 18 and 18 are connected to the upper portions of the outer masts 12 and 12 by a pair of right and left fixing devices 20 and 20 described in detail below. A fitting convex portion 21 projecting from the lower end surface of the lift cylinders 18 and 18 is fitted into a fitting hole 14a provided in the mast support 14, and the lift cylinders 18 and 18 in the lateral direction on the mast support 14 are inserted. Movement is regulated.

Since the pair of fixing devices 20, 20 are symmetrical and have the same configuration, only the right fixing device 20 will be described.
FIG. 3 is an enlarged perspective view showing the fixing device 20 that connects the upper end of the right lift cylinder 18 to the upper end of the right outer mast 12. FIG. 4 is an exploded perspective view showing the fixing device 20.

  As shown in FIG. 3, a bracket 23 having a lateral U shape is secured to the right side surface of the outer mast 12 by welding. The bracket 23 is formed by a vertical plate 23a and horizontal plates 23b and 23c that are integrally bent at both upper and lower ends of the vertical plate 23a. A mounting hole 23d is formed in the central portion of the vertical plate 23a, and a spacer 24 having a horizontal cylindrical shape is disposed laterally in the mounting hole 23d and is connected to the bracket 23 by a connecting bolt 26. .

  As shown in FIG. 3, a cap 44 is fitted and fixed to the upper end portion of the cylinder body 18 </ b> A of the lift cylinder 18, and the piston rod 19 protrudes from the upper surface of the cap 44. The bracket 23 and the upper end of the cylinder body 18A are connected by a spacer 24, a supporter body 25, and a connecting bolt 26. The supporter body 25 is detachably attached to the outer peripheral surface of the cylinder body 18A so as to correspond to the overflow pipe 22 provided in the cylinder body 18A. This supporter body 25 has a notched cylindrical body portion 25a fitted to the outer peripheral surface of the cylinder body 18A, and a pair of arm portions 25b integrally and bifurcatedly connected to both ends of the body portion 25a. , 25c. The right arm portion 25c is formed with an insertion hole 25d penetrating a connecting bolt 26 for connecting the bracket 23 and the supporter body 25. The left arm portion 25b is integrally formed with a ring-shaped female screw portion 25e corresponding to the insertion hole 25d for screwing the male screw portion of the connecting bolt 26.

  A rubber cushioning member 27 is interposed between the arm portions 25b and 25c of the supporter body 25. In this embodiment, a supporter is formed by the supporter body 25 and the buffer member 27. A surface of the buffer member 27 that contacts the outer peripheral surface of the cylinder body 18A is formed as an arc surface 27a, and an overflow pipe 22 as a projection provided on the cylinder body 18A is engaged with the lower surface thereof as shown in FIG. An engaging recess 27b is formed. Stoppers 27c and 27c for locking the supporter body 25 to the lower edges of the arm portions 25b and 25c and preventing the buffer member 27 from moving upward are integrally formed on the left and right sides of the lower end of the buffer member 27. Is formed.

Next, a method of connecting the lift cylinder 18 and the bracket 23 using the spacer 24, the supporter body 25, the connecting bolt 26, and the buffer member 27 will be described.
First, the circular arc surface 27 a of the buffer member 27 is brought into contact with the outer peripheral surface of the cylinder main body 18 </ b> A, and the engagement concave portion 27 b is engaged with the curved portion 22 a at the upper portion of the overflow pipe 22.

  Next, one end of the spacer 24 is fitted into the mounting hole 23d of the bracket 23, and the arm portions 25b and 25c of the supporter body 25 are expanded in the horizontal direction to be separated from each other by using elastic deformation of the body portion 25a. The body portion 25a is fitted and brought into contact with the outer peripheral surface of the cylinder body 18A, and the left and right side surfaces of the buffer member 27 are clamped by the arm portions 25b and 25c, and the other end surface of the spacer 24 and the inner surface of the vertical plate 23a are clamped. Clamp. In this state, the lower end edges of the arm portions 25 b and 25 c are supported by the stoppers 27 c and 27 c of the buffer member 27. Further, the insertion hole 25 d and the female screw portion 25 e correspond to the through hole 24 a of the spacer 24. In this state, as shown in FIG. 6, the connecting bolt 26 is passed through the through hole 24 a of the spacer 24, and the leading male screw portion of the connecting bolt 26 is screwed into the female screw portion 25 e of the supporter body 25.

As described above, the upper end portion of the lift cylinder 18 is fixed to the bracket 23 using the spacer 24, the supporter body 25, the connecting bolt 26 and the buffer member 27.
According to the forklift lift cylinder fixing device of the above embodiment, the following effects can be obtained.

  (1) In the above embodiment, the lift cylinder 18 is provided with the engagement recess 27b of the buffer member 27 held between the arm portions 25b, 25c of the supporter body 25 for connecting the lift cylinder 18 to the bracket 23. The bent portion 22a of the ready-made overflow pipe 22 is engaged. Further, a stopper 27c is provided at the lower end portion of the buffer member 27 so as to be engaged with the lower end edges of the arm portions 25b, 25c. For this reason, the upward movement of the lift cylinder 18 is prevented by the buffer member 27, the supporter body 25 and the bracket 23. Accordingly, parts dedicated to preventing the lift cylinder 18 from being pulled out can be omitted, and the manufacturing and assembling operations can be facilitated to reduce the cost.

  (2) In the above embodiment, the overflow pipe 22 serving as the protrusion is engaged with the engagement recess 27 b of the buffer member 27. For this reason, compared to the configuration in which the rotation screw hole 45 is formed in the cap 44 described in the background art or the configuration in which the step portion 46 is formed in the cap 44, the applicable model of the lift cylinder 18 to which the supporter body 25 can be mounted. Restrictions can be relaxed.

  (3) In the above embodiment, since the protrusion is an overflow pipe, it is not necessary to newly process a dedicated protrusion for the lift cylinder 18, and the cost can be reduced.

  (4) In the above embodiment, since the curved portion 22a of the overflow pipe 22 of the lift cylinder 18 is engaged with the engagement recess 27b of the buffer member 27, the lift cylinder 18 rotates about the vertical line. Can be prevented. For this reason, parts dedicated to preventing the rotation of the lift cylinder 18 can be omitted, the number of parts can be reduced, manufacturing and assembling operations can be easily performed, and the cost can be reduced.

  (5) In the above embodiment, since the overflow pipe 22 is held by the rubber buffer member 27, the vibration of the outer mast 12 is transmitted to the buffer member 27 via the bracket 23, the spacer 24, and the supporter body 25. Even so, vibrations acting on the overflow pipe 22 are alleviated. For this reason, fatigue due to vibration of the overflow pipe 22 can be reduced and durability can be improved.

  (6) In the above embodiment, the supporter main body 25 is formed by the body portion 25a and the arm portions 25b and 25c that can be elastically deformed. For this reason, the body 25a of the supporter body 25 can be fitted to the outer peripheral surface of the cylinder body 18A from the side of the cylinder body 18A, and the supporter body 25 can be easily attached to the lift cylinder 18. it can.

  (7) In the above embodiment, one end of the spacer 24 is fitted into the mounting hole 23d of the bracket 23, and the vertical plate 23a of the spacer 24 and the bracket 23 is placed between the ends of the arm portions 25b and 25c of the supporter body 25. The supporter body 25 is connected to the bracket 23 and the spacer 24 by a connecting bolt 26. Further, the curved portion 22a of the overflow pipe 22 is engaged with the engaging recess 27b of the buffer member 27, and a stopper 27c is integrally formed at the lower end portion of the buffer member 27, and the stopper 27c is formed at the lower end edge of the arm portions 25b and 25c. Was locked. For this reason, the buffer member 27 can be held at a predetermined position between the arm portions 25b and 25c, and a dedicated part for attaching the buffer member 27 to the supporter body 25 is omitted to simplify the structure and facilitate manufacture. The cost can be reduced.

In addition, you may change the said embodiment as follows.
As shown in FIG. 7, an engagement recess 25f that is engaged with the overflow pipe 22 from above is formed on the body 25a of the support body 25, and rubber or the like is formed between the overflow pipe 22 and the engagement recess 25f. The formed buffer member 27 may be interposed.

  As shown in FIG. 8, an air vent as a projection provided in advance in the lift cylinder 18 with respect to the body portion 25a of the support body 25 and for releasing the air in the rod side cylinder chamber of the lift cylinder 18 to the outside. An engagement recess 25f for engaging the plug 29 may be provided.

  Although not shown, instead of the overflow pipe 22 or the air vent plug 29, a protrusion may be newly attached to the outer peripheral surface of the cylinder body 18A of the lift cylinder 18 or the outer peripheral surface of the cap 44 by welding or the like.

  In the case where the cap 44 is provided with a protrusion, there is an effect of omitting a part dedicated to preventing the lift cylinder 18 from coming out and widening the model range of the lift cylinder 18 to which the support body 25 can be applied. A rotation prevention structure is required.

O You may use the overflow pipe 22 or the air vent plug 29 provided in the cap 44 as a projection part.
A connecting pin and a circlip may be used instead of the connecting bolt 26 and the female screw portion 25e as connecting means.

O You may apply to the mast assembly which raises / lowers the bracket which supported the fork with the lift cylinder 18. FIG.
The spacer 24 may be connected to the mounting hole 23d of the bracket 23 by welding.
(Definition) In this specification, the engagement recess of the supporter is not only the engagement recess formed in the supporter body 25 itself, but also the engagement recess formed in other members such as the buffer member 27 held by the supporter body 25. Shall be included.

1 is a front view of a mast assembly equipped with a fixing device for a lift cylinder of a forklift that embodies the present invention. FIG. 2 is a plan view of the mast assembly of FIG. 1. The perspective view of the fixing device of a lift cylinder. The exploded perspective view of the fixing device of a lift cylinder. The expanded longitudinal cross-sectional view of the fixing device of a lift cylinder. The expanded plane sectional view of the fixing device of a lift cylinder. The fragmentary longitudinal cross-section which shows another example of this invention. The fragmentary longitudinal cross-section which shows another example of this invention. The cross-sectional view which shows the fixing device of the lift cylinder of the conventional forklift. The front view which shows the fixing device of the lift cylinder of the conventional forklift. The front sectional view which shows the fixing device of the conventional lift cylinder. The disassembled perspective view which shows the attachment structure of the lower end part of the conventional lift cylinder.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 18 ... Lift cylinder, 18A ... Cylinder main body, 20 ... Fixing device, 22 ... Overflow pipe as projection part, 23 ... Bracket, 25f, 27b ... Engagement recessed part, 24 ... Spacer, 25 ... Supporter main body, 25a ... Trunk part, 25b, 25c... Arm portion, 26... Connecting bolt constituting the connecting means, 27... Shock absorbing member, 27c... Stopper, 29.

Claims (6)

In the lift cylinder fixing device in which a supporter for supporting the lift cylinder is attached to the bracket provided on the outer mast,
Protruding portions projecting laterally on the outer peripheral surface of the lift cylinder are provided, the projecting portions being an overflow pipe or an air vent plug provided in advance in the lift cylinder, and engaging the projecting portions with the supporter, An apparatus for fixing a lift cylinder for a forklift, comprising an engagement recess for preventing the protrusion from moving upward and turning. The forklift lift cylinder fixing device according to claim 1, wherein the protrusion is provided on a cylinder body of the lift cylinder. The forklift lift cylinder fixing device according to claim 1 or 2, wherein the supporter includes a supporter body and a buffer member, and the engaging recess is formed in the buffer member . In Claim 3 , the supporter body is constituted by a notched cylindrical body part fitted to the outer peripheral surface of the lift cylinder, and a pair of arm parts formed in a bifurcated shape at both ends of the body part, The forklift lift cylinder fixing device, wherein the arm portion is connected to the bracket by a connecting means . In Claim 4, The said buffer member is interposed between a pair of said arm parts, The engagement recessed part of the said projection part is provided in the inner surface of the buffer member which contacts the outer peripheral surface of a lift cylinder, A forklift lift cylinder fixing device, characterized in that stoppers are provided on both the left and right sides of the lower end portion to be locked to the lower end edge of the arm portion to prevent the buffer member from moving upward . 6. The spacer according to claim 4 or 5, wherein a spacer interposed between a pair of arm portions of the supporter body is disposed in the bracket, and a connecting bolt or a connecting pin as the connecting means passes through the through hole of the spacer. A lift cylinder fixing device for a forklift characterized by being provided .

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