JP2008222362A - Swing member support structure of working vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a swing member support structure of a working vehicle that can surely supply lubricating grease to the sliding surfaces of a support shaft and a bush in the swing member support structure of the working vehicle constituted to support a swing member in a swingable manner to the support shaft through the bush installed at the inner peripheral surface of a support fixedly provided at the swing member of the working vehicle and to supply the lubricating grease between the inner peripheral surface of the bush and the outer peripheral surface of the support shaft through a greasing passage penetratingly formed facing a recessed groove of the support, and a greasing port formed penetrating a projection of the bush. <P>SOLUTION: A greasing guide pipe 11 is fitted to the greasing passage 5o of the support, and the tip of the greasing guide pipe 11 is inserted in a greasing port 6o of the bush 6. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

    The present invention relates to a rocking member support structure for a work vehicle, and more particularly to a rocking member support structure for a work vehicle that is suitable for application to a structure in which a mast of a forklift is rockably supported with respect to a drive axle. .

    FIG. 8 shows a forklift (forklift truck) which is an embodiment of a work vehicle. The forklift A is equipped with a work machine W in front of a vehicle body H, and the work machine W is erected vertically. A fork F is moved up and down by a lift cylinder R along the mast M.

  Further, the mast M in the work machine W is supported so as to be swingable with respect to the vehicle body H, and based on the operation of the tilt cylinder T interposed between the vehicle body H and a predetermined angle. It is configured to tilt (forward / backward) over a range.

  Here, the mast M in the forklift A is swingably supported by a drive axle (FIG. 9) D fixedly installed at the front lower part of the vehicle main body H. It is widely used in various representative working vehicles (see, for example, Patent Document 1 and Patent Document 2).

  Specifically, as shown in FIGS. 9 and 10, a mast support S is fixedly installed at the lower rear of the mast M, and a bush B having a half-divided cylindrical shape is attached to the mast support S. A mast M (mast support S) is placed on the drive axle D via B, and a support cap C is fastened to the mast support S by bolts V and V so as to hold the drive axle D therebetween. .

  Further, a lubricating surface is provided on the sliding surface of the bush B and the drive axle D through a grease supply passage So formed in the mast support S, a grease supply port Bo formed in the bush B, and a grease groove Bg. It is configured to supply grease.

  Here, in the configuration described above, when a load in the thrust direction (axial direction in the drive axle D) is applied to the bush B, the bush B is screwed to the mast support S to prevent the bush B from moving from the mast support S. Although the important points on the outer peripheral surface of the bush B are tightened by the screw (not shown), not only does the manufacturing cost increase due to the need for screw processing on the mast support S, but also the forklift increases in size. There was a problem that could not cope with the increase in thrust load.

  Therefore, in order to eliminate the inconvenience as described above, ribs (projections) Br extending along the circumferential direction are formed on the outer peripheral surface Bf of the bush B as shown in FIGS. A configuration is provided in which the bush B is restrained from moving in the thrust direction with respect to the mast support S by being fitted with a concave groove Sg formed in the inner peripheral surface Si.

Further, in the above-described configuration, the greasing passage So formed through the mast support S and facing the concave groove Sg, and the greasing port Bo and the grease groove Bg formed through the rib Br of the bush B are provided. The lubricating grease is supplied to the sliding surface between the bush B and the drive axle D.
JP-A-6-271294 Japanese Patent Laid-Open No. 7-81895

    By the way, as described above, in the configuration in which the rib Br of the bush B is fitted into the concave groove Sg of the mast support S, the outer peripheral surface Bf of the bush B is brought into close contact with the inner peripheral surface Si of the mast support S. A gap I appears between the upper surface of Br and the bottom surface of the groove Sg due to a tolerance for avoiding interference.

  On the other hand, the grease for lubrication supplied to the sliding surface of the bush B and the drive axle D is hardened by mixing iron powder accompanying wear of the drive axle D or sand powder entering from the outside. The entire area of the grease groove Bg in the bush B and the greasing port Bo may be blocked by the fixed grease.

  Thus, when new grease is supplied (pressure fed) as indicated by the arrow G to the greasing passage So of the mast support S in a state where the greasing port Bo of the bush B is blocked by the solidified grease, the above-mentioned greasing passage Since the grease from So cannot enter the greasing port Bo of the bush B, it escapes to the gap I between the concave groove Sg and the rib Br described above, and further, the rear surface of the bush B (the meeting surface of the mast support S and the bush B) ) Leaks to the side, so that almost no new grease is supplied to the sliding surface between the drive axle D and the bush B, so that the wear of the drive axle D and the bush B due to the lack of grease is reduced. There was an inconvenience.

  In view of the above situation, an object of the present invention is to provide a rocking member support structure for a working vehicle that can reliably supply lubricating grease to the sliding surface between the support shaft and the bush.

    In order to achieve the above object, the swing member support structure for a work vehicle according to claim 1 is provided on a support shaft in the work vehicle via a bush installed on an inner peripheral surface of a support fixed to the swing member of the work vehicle. The swinging member is swingably supported with respect to the support shaft, and a concave groove is formed along the circumferential direction on the inner peripheral surface of the support, while a protrusion is formed along the circumferential direction on the outer peripheral surface of the bush. Forming and fitting a protrusion on the bush into the groove in the support to restrict the axial movement of the bush relative to the support, and a greasing passage formed through the groove facing the support; In a rocking member support structure for a working vehicle configured to supply lubricating grease between the inner peripheral surface of the bush and the outer peripheral surface of the support shaft through a greasing port formed so as to penetrate the ridge. , Greasing the support greasing passage With the fitting the Dopaipu is characterized by comprising inserting the tip of greasing the guide pipe greasing port of the bush.

  Further, the rocking member support structure for a working vehicle according to claim 2 is the same as the rocking member support structure for a working vehicle according to claim 1, wherein the circumferential dimension of the bushing of the greasing port is formed on the support. It is characterized by being configured to regulate movement of the bush relative to the support in the circumferential direction by a grease supply guide pipe that is set to be the same as the inner diameter of the grease passage and is fitted to the grease supply passage and the grease supply port.

  According to a third aspect of the present invention, there is provided a swing member supporting structure for a working vehicle, wherein the greasing guide pipe is constituted by a spring pin. .

    According to the rocking member support structure of the working vehicle related to the invention of claim 1, the greasing guide pipe is fitted into the greasing passage of the support, and the tip of the greasing guide pipe is inserted into the greasing port of the bush. Therefore, since the above-mentioned greasing guide pipe passes through the gap between the concave groove of the support and the protrusion of the bush, the grease supplied to the greasing passage of the support passes through the greasing guide pipe, The grease is surely supplied to the grease port of the bush without leaking to the outside through the gap between the concave groove of the bush and the protrusion of the bush, so that the grease is reliably supplied to the sliding surface of the support shaft and the bush. Therefore, it becomes possible to suppress wear of the bearing shaft and the bush due to the shortage of grease.

  According to the rocking member support structure for a working vehicle related to the invention of claim 2, the circumferential dimension of the bush of the greasing port is set to be the same as the inner diameter of the greasing passage formed in the support. The greasing guide pipe fitted to the greasing passage and the greasing port restricts the movement of the bushing relative to the support in the circumferential direction, so there is no need to use dedicated fixing means, in other words, an inadvertent increase in the number of parts. Without being accompanied, it becomes possible to prevent the circumferential displacement of the bush.

  According to the rocking member support structure for a working vehicle related to the invention of claim 3, the grease supply guide pipe is composed of a spring pin, and therefore the grease supply guide can be elastically deformed in the radial direction of the spring pin. The accuracy of the greasing passage and the greasing port into which the pin is fitted may be rough and can be processed at a low cost, so that the manufacturing cost can be reduced.

Hereinafter, the present invention will be described in detail with reference to the drawings illustrating embodiments.
1 to 5 show an embodiment in which a rocking member support structure according to the present invention is applied to a forklift (forklift truck) which is an aspect of a working vehicle. A work machine 3 is mounted on the front side, and the work machine 3 is configured to move the fork 3F up and down by a lift cylinder 3R along a mast 3M provided up and down.

  A mast (swing member) 3M in the work machine 3 is supported so as to be swingable with respect to a drive axle (support shaft) 4 fixedly installed at a lower front portion of the vehicle body 2. Based on the operation of the tilt cylinder 3T interposed therebetween, it is configured to be able to tilt (forward / backward tilt) over a predetermined angle range.

  2 and 3, a mast support (support) 5 is fixedly installed at the lower rear of the mast 3M, and a bush 6 having a half-cylindrical shape is mounted on the mast support 5. The mast 3M (and the mast support 5) is mounted on the drive axle 4 through the support 6 and a support cap 7 is fastened to the mast support 5 with bolts 8 and 8 so as to hold the drive axle 4 therebetween. Yes.

  As shown in FIG. 4, the bush 6 attached to the mast support 5 is formed with ribs 6r extending along the circumferential direction on the outer peripheral surface 6f, while extending vertically and horizontally on the inner peripheral surface 6i. A grease groove 6g is formed, and two grease supply ports 6o and 6o are formed which pass through the rib 6r and open to the inner peripheral surface 6i (grease groove 6g).

  Here, the two greasing ports 6o, 6o in the bush 6 are formed in parallel with each other in consideration of the mold forming process, and are attached to the support 5 even in the posture in which the right and left in the figure are reversed. In order to be able to be used, they are formed at positions that are mirror surfaces with respect to each other with a center line (not shown) on the left and right in the figure.

  As shown in FIGS. 3 and 5, the rib 6 r formed on the outer peripheral surface 6 f (see FIG. 5) of the bush 6 is fitted with the concave groove 5 g formed on the inner peripheral surface 5 i (see FIG. 5) of the mast support 5. Thus, the movement of the bush 6 in the thrust direction relative to the mast support 5 is restricted.

  On the other hand, the mast support 5 is formed with a greasing passage 5o penetratingly formed at a position corresponding to the greasing port 6o of the bush 6 attached to the mast support 5 so as to face the concave groove 5g. A grease supply guide pipe 10 made of a spring pin is fitted and installed at the end of the grease passage 5o.

  Further, the tip of the greasing guide pin 10 is inserted into the greasing port 6o of the bush 6, and the grease supplied to the greasing passage 5o of the mast support 5 as shown by the arrow G (FIG. 5) The grease is supplied from the greasing passage 5 o to the greasing port 6 o of the bush 6 through the greasing guide pin 10.

  Here, in the configuration in which the rib 6r of the bush 6 is fitted in the concave groove 5g of the mast support 5, the clearance I caused by the tolerance for avoiding interference between the upper surface of the rib 6r and the bottom surface of the concave groove 5g. (FIG. 5) appears. As described above, the greasing guide pipe 10 is fitted into the greasing passage 5o of the mast support 5, and the tip of the greasing guide pipe 10 is connected to the greasing port 6o of the bush 6. The grease supply guide pipe 10 that vertically cuts the gap I between the groove 5g and the rib 6r functions as a wall that covers the gap I.

  For this reason, the grease supplied to the greasing passage 5o of the mast support 5 does not leak outside through the gap I between the concave groove 5g and the rib 6r by passing through the greasing guide pipe 10. Thus, the grease is reliably supplied to the sliding surface with the drive axle 4 through the grease groove 6g, so that the drive axle 4 and the bush 6 caused by the shortage of grease are supplied. Wear is suppressed.

  Further, in the above-described embodiment, the grease supply guide pipe 10 is composed of a spring pin, and the grease supply guide pin 10 is fitted by the characteristic that the spring pin can be elastically deformed in the radial direction. Since the shape accuracy of the passage 5o and the greasing port 6o may be rough and can be processed at low cost, it is possible to reduce the manufacturing cost of the swinging member support structure and hence the manufacturing cost of the forklift 1. It becomes possible.

  Incidentally, the spring pin constituting the greasing guide pipe 10 is formed into a pipe shape by winding a thin plate of a spring material one or more times, and has a characteristic capable of elastic deformation (reduction / expansion) in the radial direction. As is well known.

  6 and 7 show another embodiment of the swinging member support structure according to the present invention. In this embodiment, the greasing port 6o 'of the bush 6' is connected to the greasing passage 5o of the mast support 5. The greasing guide pipe 10 made of a spring pin is fitted and installed in the same direction as the grease, and the greasing port 6o 'in the bush 6' has at least a circumferential dimension in the bush 6 '. The inner diameter of the greasing passage 5o in the support 5 is set to be the same.

  Here, as shown in FIG. 7, two bushes 6o 'and 6o' are formed through the bush 6 ', and these grease ports 6o' and 6o 'are reversed right and left in the figure. Even in such a posture, they are formed at positions that are mirror-surfaced with respect to each other with a center line (not shown) on the left and right in the figure so that the support 5 can be mounted and used.

  In the above-described embodiment, there is no fundamental difference from the configuration shown in FIGS. 1 to 5 except that the shape of the greasing port 6o ′ in the bush 6 ′ is different. 1 to 5 are designated by the same reference numerals as those in FIGS. 1 to 5 and detailed description thereof is omitted.

  According to the configuration of the above-described embodiment, the circumferential dimension of the bush 6 ′ of the greasing port 6 o ′ is set to be the same as the inner diameter of the greasing passage 5 o in the mast support 5. The outer diameter of the greasing guide pipe 10 installed together coincides with the circumferential dimension of the bush 6 'of the greasing port 6o'.

  Therefore, by inserting the tip of the greasing guide pipe 10 into the greasing port 6o ′ of the bush 6 ′, the movement of the bush 6 ′ in the circumferential direction relative to the mast support 5 is restricted by the greasing guide pipe 10. Will be.

  Therefore, according to the above-described configuration, the bushing 6 'can be positioned (fixed) with respect to the mast support 5 without using a dedicated fixing means, in other words, without unnecessarily increasing the number of parts. This is an extremely effective configuration for cost reduction.

  Further, according to the above configuration, the greasing guide pipe 10 is fitted into the greasing passage 5o of the mast support 5 and the greasing guide pipe 10 as in the swing member supporting structure shown in FIGS. Is inserted into the grease port 6o 'of the bush 6' so that the grease can be reliably supplied to the sliding surface with the drive axle 4, and the wear of the drive axle 4 and the bush 6 'due to the lack of grease. Needless to say, it can be suppressed.

  Furthermore, according to the above configuration, since the grease supply guide pipe 10 is configured by the spring pin, the manufacturing cost and the extension of the swinging member support structure are increased in the same manner as the swinging member support structure shown in FIGS. Thus, the manufacturing cost of the forklift 1 can be reduced.

  In each of the above-described embodiments, the example in which the swing member support structure according to the present invention is applied to the support structure of a work machine (mast) in a forklift that is an aspect of the work vehicle is shown. Various working vehicles other than forklifts can be used as long as the working vehicle supports the swinging member swingably with respect to the support shaft via a bush installed on the inner peripheral surface of the support fixed to the moving member. However, it goes without saying that the present invention can be effectively applied.

The whole side view of the forklift which shows one Example of this invention. The side view which shows the structure of the mast periphery in the forklift of FIG. The cross-sectional side view which shows the structure of the mast support periphery in the forklift of FIG. (a) And (b) is the side view and inner surface figure of the mast bush in the forklift of FIG. FIG. 5 is a sectional end view conceptually showing a cross section taken along line VV in FIG. 3. The cross-sectional side view which shows the other structure of the mast support periphery in the forklift of FIG. (a) And (b) is the side view and inner surface figure of the mast bush in FIG. The whole side view which shows notionally the structure of the forklift which is one aspect | mode of a working vehicle. The side view which shows the structure of the mast periphery in the conventional forklift. The cross-sectional side view which shows the structure around the mast support in the conventional forklift. Sectional side view which shows the other structure of the mast support periphery in the conventional forklift. XII-XII line sectional view in FIG.

Explanation of symbols

1 ... Forklift (work vehicle),
2 ... the vehicle body,
3 ... Work machine,
3M ... Mast (rocking member),
4 ... Drive axle (bearing shaft),
5 ... Mast support (support),
5g ... concave groove,
5o ... greasing passage,
6, 6 '... Bush,
6r, 6r '... ribs (projections),
6o, 6o '... Greasing port,
7 ... Support cap,
10 ... Greasing guide pipe.

Claims (3)

Supporting the swinging member with respect to the support shaft so as to be swingable with respect to the support shaft of the working vehicle via a bush installed on an inner peripheral surface of a support fixed to the swinging member of the working vehicle; While forming a concave groove along the circumferential direction on the inner peripheral surface of the support, a convex line is formed along the circumferential direction on the outer peripheral surface of the bush, and the convex line of the bush is formed in the concave groove of the support. It is fitted to restrict the movement of the bush in the axial direction with respect to the support, and is formed through the grease supply passage formed so as to penetrate the concave groove of the support and the protruding line of the bush. In a swing member support structure for a working vehicle configured to supply lubricating grease between the inner peripheral surface of the bush and the outer peripheral surface of the support shaft through the lubricated port,
A rocking member support for a working vehicle, wherein a greasing guide pipe is fitted into the greasing passage of the support, and a tip of the greasing guide pipe is inserted into the greasing port of the bush. Construction.     The greasing guide pipe having a circumferential dimension in the bush of the greasing port set equal to the inner diameter of the greasing passage formed in the support, and fitted to the greasing passage and the greasing port. 2. The swing member supporting structure for a working vehicle according to claim 1, wherein movement of the bush in the circumferential direction with respect to the support is restricted by the support.     2. The rocking member support structure for a working vehicle according to claim 1, wherein the grease supply guide pipe is constituted by a spring pin.

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