JP2002349510A - Hydraulic elevation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dust cover capable of being post-attached to a piston rod simply, having a good durability, and capable of protecting the piston rod against hopping stones, etc., certainly. SOLUTION: A hydraulic elevation device 10 is configured so that a mounting metal piece 101 is attached to the end of the piston rod 33 of its cylinder device 21 and fixed by an upper nut 102 and a lower nut 103 screwed fast to its top and bottom at the ends of the piston rod 33, wherein a mounting part 104A of the dust cover 104 is welded to the lower nut 103.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic lifting device suitable for use in agricultural machines and the like.

[0002]

2. Description of the Related Art In a hydraulic elevating device used in an agricultural machine or the like, an end of a piston rod protruding from a cylinder is provided with a cylindrical shape in order to protect a piston rod extending and contracting from a cylinder of a cylinder device from flying stones or the like. The dust cover is installed.

In assembling a cylinder device, a piston rod is inserted through an opening of a cylinder, and after sub-assembly for sealing the opening with a rod guide and an oil seal, hydraulic oil is evacuated to the inside of the cylinder. Here, if the dust cover is attached to the piston rod from the beginning, the dust cover hinders the assembly of the rod guide etc. into the opening of the cylinder into which the piston rod is inserted. Must be retrofitted to rod.

[0004] As a conventional technique of retrofitting a dust cover to a piston rod, (1) a method in which both upper and lower ends of a bellows-shaped rubber dust cover are fixed to both a piston rod and a cylinder with a band (Japanese Patent Laid-Open No. 2000-53393); (2) There is a type in which a dust cover (cylinder cover) separate from a cylinder device is fastened together with a fitting provided at an end of a piston rod to a vehicle body side of a work vehicle (practical use 2504595).

[0005]

The prior art has the following problems. The bellows-shaped rubber dust cover has low durability against stepping stones and the like. In addition, fixing the upper and lower ends of the dust cover with bands requires a lot of work.

When the dust cover is separate from the cylinder device, the transportability of the dust device before the cylinder device and the dust cover are assembled to the work vehicle is poor.

An object of the present invention is to provide a dust cover that can be easily attached to a piston rod, has good durability, and reliably protects the piston rod from flying stones.

[0008]

According to a first aspect of the present invention, a mounting bracket is provided at an end of a piston rod of a cylinder device, and upper and lower nuts which are screwed up and down of the mounting bracket at the end of the piston rod. In this case, the mounting portion of the dust cover is welded to the lower nut in the hydraulic lifting device in which the mounting bracket is fixed.

According to a second aspect of the present invention, in addition to the first aspect, the dust cover includes a mounting plate welded to the lower nut, and a cover cylinder joined to the mounting plate.

[0010]

According to the first aspect of the present invention, the following effects are obtained. Since the dust cover is welded to the lower nut, it can be formed of a hard material such as iron, and can improve durability.

The dust cover can be welded to the lower nut in advance, and the dust cover can be mounted simultaneously with screwing the lower nut to fix the mounting bracket to the piston rod. Can be reduced.

The dust cover is welded to a lower nut for fixing the mounting bracket to the piston rod, and the dust cover can be easily retrofitted to the piston rod after sub-assembly of the cylinder device.

The dust cover is welded to the lower nut for fixing the mounting bracket to the piston rod. There is no need to perform any special groove processing, step processing, or the like for mounting the dust cover on the piston rod. Good rod workability.

According to the second aspect of the invention, the following effects are obtained. Since the dust cover is made up of the mounting plate and the cover cylinder, the weight of the dust cover can be reduced by using iron for the mounting plate and resin for the cover cylinder.

[0015]

1 is a longitudinal sectional view showing a hydraulic elevating device, FIG. 2 is a transverse sectional view of FIG. 1, FIG. 3 is a sectional view showing a dust cover, and FIG. 4 is a sectional view showing a modified example of a dust cover. FIG.

As shown in FIGS. 1 and 2, a hydraulic lifting device 10 such as an agricultural machine has a cylinder device 21 interposed between a vehicle body such as an agricultural machine and a portion to be raised and lowered. By controlling the supply and discharge of the working oil to and from the cylinder device 21, the piston rod 33 of the cylinder device 21 is expanded and contracted so that the portion to be raised and lowered can be moved up and down.

The cylinder device 21 includes a hydraulic oil supply / discharge device 11
Are integrated with a valve block 65 described later. That is, the cylinder device 21 has an outer cylinder 31 and an inner cylinder 32 formed of a drawn steel pipe, and the cylinders 31 and 32 are connected to the valve block 6.
5 are integrally connected. The valve block 65 is made of, for example, an aluminum alloy casting, and has a mounting pin insertion hole 65A to a vehicle body such as an agricultural machine.

Further, the cylinder device 21 has a piston rod 33 used by being connected to an ascending / descending portion of an agricultural machine or the like. The piston rod 33 is moved from a rod guide 34 provided at the open end of the outer cylinder 31 to It is inserted into the oil chamber 35 of the inner cylinder 32 so as to be able to expand and contract. Rod guide 34
Includes a bush 36 that slides on the piston rod 33 and an oil seal 37.

The cylinder device 21 includes the inner cylinder 3
A piston 39 is fixed to an end of the piston rod 33 in the second oil chamber 35 with a nut 38. Piston 3
9 includes a seal member 41 such as an O-ring that slides on the inner surface of the inner cylinder 32, and
The first oil chamber 35 </ b> A on the side that houses
And the second oil chamber 35 </ b> B on the side where no oil is stored.

The cylinder device 21 has a large diameter hole 42A, a medium diameter hole 42B, and a small diameter hole 42C concentric with the valve block 65, and the concentric large diameter portion 43 with the rod guide 34.
A, a small diameter portion 43C is provided. One end of the outer cylinder 31 is fitted into the large-diameter hole 42A of the valve block 65 via a sealing member 44 such as an O-ring, and the other end of the outer cylinder 31 is fitted into the large-diameter portion 43A of the rod guide 34. Then, the caulking portion 46 fixes the washer 46A via the mandrel 45 of the oil seal 37. Further, one end of the inner cylinder 32 is fitted into the small diameter hole 42C of the valve block 65 via a sealing member 47 such as an O-ring, and the other end of the inner cylinder 32 is fitted into the small diameter portion 43C of the rod guide 34. And fix it. Thus, a ring space-like oil passage 48 is formed between the outer cylinder 31 and the inner cylinder 32, and the first oil chamber 35A
Oil passage 49A formed in the inner end surface of rod guide 34 and oil passage 48, and oil hole 49B cut out in the other end of inner cylinder 32.
Contact at The oil passage 48 communicating with the first oil chamber 35A is connected to the first oil passage 66A communicating with the medium diameter hole 42B of the valve block 65, and the second oil chamber 35B is connected to the valve block 6.
5 respectively.

The cylinder device 21 includes a rod guide 3
4 is provided with an oil hole 50 penetrating across the inner end face and the outer end face (end face on the side of the oil seal 37), and the piston rod 33 passes through the bush 36 from the first oil chamber 35A and the outer end face of the rod guide 34. The hydraulic oil raked up to the side of the oil hole 50
To the first fat 35A.

In the cylinder device 21, an iron collar 51 is inserted and mounted directly above the piston 39 on the outer periphery of the piston rod 33, and the collar 51 is inserted into the rod guide 34 when the piston rod 33 is extended and cut. The maximum extension stroke is regulated by abutting against the end face.

Here, a configuration in which the cylinder device 21 is connected to the valve block 65 will be described.

(1) The large diameter hole 42A of the valve block 65 is provided with a ring groove 65B having an arc-shaped cross section. One end of the outer cylinder 31 is inserted into the large-diameter hole 42A, and one end of the outer cylinder 31 is bulged by bulging to form a bulge 52, and the bulge 52 is engaged with the ring groove 65B. Combine. In this bulging process, an elastic body such as urethane inserted into the outer cylinder 31 is pressurized by a pressurizing piston (the pressurization of the liquid sealed in the outer cylinder 31 or the expansion of the split ring inserted into the outer cylinder 31 are also possible). Then, the outer cylinder 31 is deformed so as to follow the ring groove 65B of the valve block 65, or the like.

(2) Insert the assembly of the inner cylinder 32 into the outer cylinder 31 fixed to the valve block 65 by the above (1), and connect one end of the inner cylinder 32 to the valve block 6.
5 is fitted into the small diameter hole 42C. In the assembly of the inner cylinder 37, the piston 39, the piston rod 33, the rod guide 34, and the like are assembled in the inner cylinder 32 before insertion into the outer cylinder 31.

(3) The swaging portion 4 at the other end of the outer cylinder 31
6 is caulked around the rod guide 34 of the inner cylinder 32 assembly.

(Hydraulic oil supply / discharge device 11) Hydraulic oil supply / discharge device 1
Reference numeral 1 denotes a reversible motor 61, a reversible gear pump 62, a tank 63, a flow path with a switching valve (not shown), and a first oil passage 66A and a second oil passage 66B provided in the valve block 65.
, The hydraulic oil can be supplied to and discharged from the first oil chamber 35A and the second oil chamber 35B of the cylinder device 21.

At this time, the hydraulic oil supply / discharge device 11 forms a flow path with a switching valve by a valve block 65 made of an aluminum alloy casting, and includes a first oil passage 66A, a second oil passage 66B, and the like. Then, the valve block 65 is connected to the cylinder device 21.
A large-diameter hole 42A, a medium-diameter hole 42B, and a small-diameter hole 42C are provided as described above, and a pump chamber 67 is provided at a position close to the integral coupling portion of the cylinder device 21. The pump chamber 67 accommodates hydraulic oil,
The pump 62 is provided so as to be immersed in the hydraulic oil. The pump 62 is fixed to the valve block 65 with bolts 68.

However, the hydraulic oil supply / discharge device 11 is provided above the pump chamber 67 provided in the valve block 65.
A motor 61 for driving the
The tank 63 is composed of a tank housing 74 that covers the tank 63. Then, the motor 61 fixes the end plate 72 to the opening at the lower end of the iron yoke 70 via a seal member such as an O-ring while fixing the end plate 72 in a liquid-tight manner. The portion around the pump chamber 67 of the valve block 65 is fitted into the lower step 72B, and the O-ring 8
1, the tank housing 74 is fitted to the upper step portion 72A, and the O-ring 82 is used for liquid-tight sealing.
The tank housing 74 and the end plate 72 are fastened to the valve block 65 with bolts 73. The details will be described below.

The hydraulic oil supply / drainage device 11 connects the mounting portion 70B of the mounting seat 70A of the iron yoke 70 of the motor 61 with the set screw 71.
With this, it is fixed to the synthetic resin end plate 72 for the motor 61. The lead wire 91 of the motor 61 is drawn out from the side of the end plate 72 to the outside. The end plate 7 of the motor 61
2 is a mounting seat 74 of the tank housing 74 with bolts 73.
A is fixed around the pump chamber 67 of the valve block 65 together with the mounting portion 74B of A, and seals the pump chamber 67.
An output shaft 61A of the motor 61 is connected to a driven shaft of the pump 62 through the end plate 72 in a liquid-tight manner.

The hydraulic oil supply / discharge device 11 includes a motor 61
The yoke 70 of the motor 61 is formed by a synthetic resin tank housing 74 having a cylindrical shape along the outer shape of the yoke 70.
And the tank housing 74 is connected to the bolt 7
3 and the valve block 65 together with the end plate 72 of the motor 61
To form a tank 63, and a space between the tank housing 74 and the yoke 70 of the motor 61 is referred to as a tank chamber 75. The tank housing 74 has an oil supply plug 92 at the oil supply port.

However, in the cylinder device 21,
An upper and lower nut 102 which is attached to the end of the piston rod 33 with a mounting bracket 101 to be moved up and down such as an agricultural machine, and which is screwed up and down on the mounting bracket 101 at the end of the piston rod 33.
The mounting bracket 101 is fixed by 103. The piston rod 33 and the mounting bracket 101 may be provided with a D-surface processing or a double-side processing for preventing the mounting bracket 101 from rotating with respect to the piston rod 33 on each of the outer peripheral surface of the piston rod 33 and the mounting hole surface of the mounting bracket 101. it can.

Then, as shown in FIG.
Of the dust cover 104 was welded to the lower end surface of the. The dust cover 104 is an integrally molded product having an iron cylindrical shape. The top surface portion is a mounting portion 104A, the piston portion 33 is covered by the cylindrical portion 104B, and the sliding surface of the piston rod 33 is stepped by stones and dust. Protect from etc. The lower nut 103 is a welding nut, and the mounting portion 104A of the dust cover 104 can be spot-welded.

The lower nut 103 can be welded to the lower end surface of the mounting bracket 101.

According to the present embodiment, the following operations are provided. Since the dust cover 104 is welded to the lower nut 103, the dust cover 104 can be formed of a hard material such as iron, and the durability can be improved.

The dust cover 104 can be welded to the lower nut 103 in advance, and the dust cover 104 can be attached at the same time as the lower nut 103 is screwed to fix the mounting bracket 101 to the piston rod 33. The man-hour for mounting the dust cover 104 can be reduced.

The dust cover 104 is welded to the lower nut 103 for fixing the mounting bracket 101 to the piston rod 33. The dust cover 104 can be easily attached to the piston rod 33 after the sub-assembly of the cylinder device 21.

The dust cover 104 is welded to the lower nut 103 for fixing the mounting bracket 101 to the piston rod 33. Special groove processing, stepping processing, and the like for mounting the dust cover 104 on the piston rod 33 are performed. There is no need to apply it, and the workability of the piston rod 33 is good.

The dust cover 105 shown in FIG. 4 is a modified example of the dust cover 104, and includes a mounting plate 105A welded to the lower nut 103 and a cover cylinder 105B engaged with and joined to the outer edge of the mounting plate 105A. It consists of The weight of the dust cover 105 can be reduced by making the mounting plate 105A of iron and the cover cylinder 105B of resin. The cover cylinder 105B may be engaged with an attachment plate 105A integral with the lower nut 103 before screwing the lower nut 103 onto the piston rod 33, or after screwing the lower nut 103 onto the piston rod 33. May be engaged with the mounting plate 105A which is integral with the mounting plate 105A.

The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration of the present invention is not limited to this embodiment, and the design can be changed within the scope of the present invention. The present invention is also included in the present invention.

[0041]

As described above, according to the present invention, it is possible to obtain a dust cover which can be easily retrofitted to a piston rod, has good durability, and reliably protects the piston rod from flying stones.

[Brief description of the drawings]

FIG. 1 is a vertical sectional view showing a hydraulic lifting device.

FIG. 2 is a cross-sectional view of FIG.

FIG. 3 is a sectional view showing a dust cover.

FIG. 4 is a sectional view showing a modification of the dust cover.

[Explanation of symbols]

 Reference Signs List 10 Hydraulic lifting device 21 Cylinder device 33 Piston rod 101 Mounting bracket 102 Upper nut 103 Lower nut 104, 105 Dust cover 105A Mounting plate 105B Cover cylinder

Claims (2)

[Claims] 1. A hydraulic lifting device in which a mounting bracket is provided at an end of a piston rod of a cylinder device, and the mounting bracket is fixed by upper and lower nuts screwed up and down on the mounting bracket at the end of the piston rod. 3. The hydraulic lift device according to claim 1, wherein a mounting portion of the dust cover is welded to the lower nut. 2. The hydraulic lifting device according to claim 1, wherein the dust cover includes a mounting plate welded to the lower nut, and a cover cylinder joined to the mounting plate.