JP2002266813A - Cylinder cover for fluid pressure cylinder and fluid pressure cylinder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the dispersion of cushioning effect by minimizing the channel resistance of a restriction passage. SOLUTION: This cylinder cover is provided with a cushion hole 3 for inserting a cushion boss mounted on a piston sliding on an inner peripheral face of a cylinder tuber to be opened on an inner end face faced to a cylinder chamber, and a hole 38 for the restriction passage, located adjacent to the cushion hole 34 through a partitioning part 36b, the cushion hole 34 has an expanded hole part 34b as a part faced to the partitioning part 36b inside of the cushion hole 34, on a position radially expanded with respect to the opening part 34k of the cushion hole 34, and a thickness of the partitioning part 36b is determined to be smaller than a distance between the opening par 34k of the cushion hole 34 and an opening part 35bk of the hole 35b for the throttle channel.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a cylinder cover and a hydraulic cylinder for a hydraulic cylinder.

[0002]

2. Description of the Related Art Conventionally, hydraulic cylinders such as hydraulic cylinders, pneumatic cylinders, and hydraulic cylinders have been used for various industrial machines, business machines, and general machines.

FIG. 10 is a sectional view showing the structure of a general hydraulic cylinder 1. The fluid pressure cylinder 1 includes a cylinder tube 11, a piston 12 sliding on an inner peripheral surface of the cylinder tube 11, a piston rod 13 connected to the piston 12, a rod cover 14j, a head cover 15j, and four tie bolts (not shown). Become. The piston 12 is provided with cushion bosses 21 and 22 on both sides thereof.

A head cover 15j, which is one of the cylinder covers, has a cushion hole 81 into which the cushion boss 22 is inserted, throttle passage holes 82 and 83, and a port PT2.
Is provided. A throttle adjustment valve 84 is mounted in the throttle passage holes 82 and 83.

When the piston 12 moves to the right in the figure and the cushion boss 22 fits into the cushion hole 81, the fluid in the cylinder chamber CR2 is confined, and the throttle passage holes 82, 8 are formed.
The fluid can be discharged only through the valve 3 and the throttle adjusting valve 84. As a result, a back pressure is generated in the cylinder chamber CR2, and a cushion effect is obtained.

[0006]

However, in the conventional head cover 15j, since both the throttle passage holes 82 and 83 are formed by drilling, the number of processing steps and the processing time are increased accordingly, and the manufacturing cost is increased. I have.

[0007] In addition, a drilled throttle passage hole 82,
Since the effective area of 83 is small and the flow path is long, the flow path resistance in this part is large. Therefore, for example, the flow rate of the pressure oil flowing through the throttle passage holes 82 and 83 fluctuates due to a change in viscosity due to a change in oil temperature, and the cushion effect varies.

[0008] As a result, the cushion effect may become unstable at the time of start-up or in the morning, such as when the cushion is too effective, and when the driving is performed for a predetermined time, the cushion effect becomes poor.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to reduce the variation in cushion effect by reducing the flow path resistance of a throttle flow path as much as possible and to reduce the manufacturing cost. .

[0010]

A cylinder cover according to the present invention has an opening at an inner end face facing a cylinder chamber.
A cushion hole into which a cushion boss provided on a piston sliding on the inner peripheral surface of the cylinder tube is inserted, and a throttle channel hole adjacent to the cushion hole and a partition wall are provided, and the cushion hole is provided. An expansion hole portion, which is a portion facing the partition portion, is provided at a position radially wider than the opening of the cushion hole, whereby the thickness of the partition portion is reduced by the thickness of the cushion hole. It is set smaller than the distance between the opening and the opening of the aperture for the throttle channel.

Preferably, the cylinder cover is surrounded by four outer peripheral surfaces and has a square shape when viewed from the front, and the expansion hole, the partition, and the throttle passage hole are each provided with three of the above-described three holes. Three holes are provided at positions facing the outer peripheral surface, and a port hole communicating with the cushion hole is provided on the other outer peripheral surface.

The opening of the aperture for the throttle channel has an arc shape centered on the center of the cushion hole. Further, a circumferential groove is provided on the inner end surface at a position including an opening of the aperture for the throttle channel.

Further, at least one of the partition walls has
A communication hole communicating the cushion hole and the throttle channel hole is provided. Further, a valve hole is provided on an outer peripheral surface facing the partition wall for mounting a throttle valve inserted into the communication hole and adjusting the throttle amount.

[0014] An air vent hole for mounting an air vent valve in communication with the throttle channel hole is provided in parallel with the valve hole.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An example in which the cylinder cover of the present invention is applied to a head cover 15 of a hydraulic cylinder 1 shown in FIG. 10 will be described below.

The head cover as a finished product is denoted by reference numeral "15", and the head cover before processing, that is, the head cover immediately after being manufactured by casting, is denoted by reference numeral "15".
B ". The same applies to the rod cover 14.

FIG. 1 is a sectional side view of the head cover 15 according to the present invention, FIG. 2 is a front view of the head cover 15 of FIG. 1 as viewed from the direction of the arrow II, and FIG.
FIG. 4 is a cross-sectional view taken along line III of FIG.
5 is a cross-sectional view of the head cover 15B before processing at the same position as FIG.

Referring mainly to FIGS. 1 to 3, the head cover 15 is surrounded by four outer peripheral surfaces 31a to 31d and has a square shape when viewed from the front. Inner end face 3 facing cylinder chamber CR2
2 and an outer end face 33 on the opposite side.

The head cover 15 is provided with one cushion hole 34 and three throttle passage holes 35a adjacent to each other with the cushion hole 34 and the partition walls 36a, 36b and 36c interposed therebetween so as to open to the inner end surface 32. 35b, 35c
Is provided.

The throttle passage holes 35a, 35b, 35c are
Each is independent, and each opening 35ak, 3
5bk and 35ck extend in an arc shape centered on the center position of the cushion hole 34. The aperture 3 for the throttle channel
5a, 35b, and 35c may be configured so that adjacent ones communicate with each other.

The cushion hole 34 has a partition 3 inside the cushion hole 34.
6a, 36b, and 36c, which are portions facing the expansion holes 34
a, 34b, 34c are provided at positions radially wider than the opening 34k of the cushion hole 34.
Thereby, the thickness d of the partition portions 36a, 36b, 36c is set.
1 is an opening 34k of the cushion hole 34 and openings 35ak, 35bk of the throttle passage holes 35a, 35b, 35c.
The distance is set to be smaller than the distance L1 from 35ck.

As described above, the extension holes 34a, 34b, 3
4c, the partition walls 36a, 36b, 36c, and the throttle passage holes 35a, 35b, 35c are provided at three positions at positions facing the three outer peripheral surfaces 31a, 31b, 31c, respectively.

The other outer peripheral surface 35d is provided with a port PT2 communicating with the cushion hole 34. A peripheral groove is formed in the opening of the cushion hole 34, and a cushion packing 50 is mounted therein. The cushion boss 22 provided on the piston 12 is closely fitted into the cushion packing 50. When the cushion boss 22 is fitted, the flow path is blocked by the cushion packing 50, and when the cushion boss 22 comes off, the cushion packing 50 forms a flow path. That is, the cushion packing 50 has a check function. Such a cushion packing 50 is known.

The inner end face 32 has holes 35a, 3
A circumferential concave groove 37 is provided at a position including the openings 35ak, 35bk, 35ck of 5b, 35c. A ring-shaped projection 44 is provided outside the concave groove 37.
At the bottom of the concave groove 37, a seal member is mounted for sealing with the end face of the cylinder tube 11 abutting.

One of the three partitions 36b
Is provided with a communication hole 38 for communicating the cushion hole 34 and the throttle channel hole 35b. A valve hole 39 is provided on the outer peripheral surface 31b facing the partition wall portion 36b. The valve hole 39 is provided with a throttle valve 51 which is inserted into the communication hole 38 and adjusts the throttle amount.

An air vent hole 40 is provided in parallel with the valve hole 39 so as to communicate with the same throttle passage hole 35b to which the throttle valve 51 is attached. In the air vent hole 40,
An air vent valve 52 is mounted.

At four corners of the head cover 15, holes 42a to 42d for inserting tie bolts are provided. 4 and 5, the head cover 15B before processing is provided with a straight port hole 43 at the port PT2. Port hole 4
3 is formed into a port PT2 by being tapered.

The inner end face 32B, the concave groove 37B provided on the inner end face 32B, and the ring-shaped protrusion 44B are cut by machining to become the inner end face 32, the concave groove 37, and the ring-shaped protrusion 44, respectively. .

By cutting the inner end face 32B,
It becomes the contact surface of the piston. By cutting the concave groove 37B and the ring-shaped protrusion 44B, the seal member is attached to the bottom as described above.

The head cover 15B is manufactured by precision casting as described above. In addition, it is also possible to manufacture by resin molding using a synthetic resin material. In the head cover 15 described above, the partition walls 36a, 36b, 3
Since the thickness of 6c is small, the communication hole 38 is short, and the flow path resistance is small. The openings 35ak, 35bk, 35ck of the throttle passage holes 35a, 35b, 35c are expanded in an arc shape, thereby increasing the effective area, thereby reducing the passage resistance. For this reason, when pressure oil is used as the pressurized fluid, for example, variation in the cushion effect due to a change in oil temperature is greatly reduced.

As a hole for adjusting the cushion, it is only necessary to form the communication hole 38 by drilling, and it is not necessary to drill a hole from the inner end face 32 as in the prior art. The manufacturing cost can be reduced.

Since the communication hole 38 and the valve hole 39 can be processed coaxially, the processing is easy. Further, in order to mount the air vent valve 52, it is only necessary to provide the air vent hole 40, and processing is easy.

Since the throttle passage holes 35a, 35b and 35c are hollow, processing of the valve hole 39 can be minimized.
Processing is easy. The valve hole 39 and the air vent hole 4
Some or all of the pilot holes may be formed during casting.

In the cushion hole 34, the extension holes 34a, 34
b, 34c, the head cover 1
The material of No. 5 is saved accordingly, and the weight is reduced. Next, the throttle valve 51 and the air vent valve 52 will be described in detail.

FIG. 6 is a plan view of the throttle valve 51, and FIG. 7 is a sectional view of the throttle valve 51. In these figures, throttle valve 51
Has a rectangular parallelepiped piece member 61 and a valve body 62. A screw hole 61a is provided inside the piece member 61, and a round hole 61b is provided on the upper surface portion.

The bridge member 61 fits into a square valve hole 39 provided on the outer peripheral surface 31b of the head cover 15. The outer peripheral surface 31b of the portion 64 in the vicinity of the piece member 61 is swaged with a punch or the like to prevent slipping. Therefore, attachment is easy.

In the screw hole 61a of the bridge member 61, a valve body 62 is provided.
A screw provided on the outer periphery of the screw is engaged. A hexagonal wrench is inserted into a hexagonal hole provided in the head of the valve body 62 through a round hole 61b and rotated. Even when the valve body 62 is loosened, it does not come off by hitting the upper surface of the piece member 61. Therefore it is safe. A seal (O-ring) 63 seals between the shaft portion 62b of the valve body 62 and the inner peripheral surface of the round hole 39b.

FIG. 8 is a plan view of the air vent valve 52, and FIG.
FIG. 3 is a cross-sectional view of the air vent valve 52. In these figures, the air bleeding valve 52 includes a rectangular parallelepiped piece member 71, a screw member 72, and a hard ball 74. A screw hole 71a is provided inside the piece member 71, and a round hole 71b is provided on the upper surface portion.

The bridge member 71, like the bridge member 61, has a square valve hole 4 formed on the outer peripheral surface 31b of the head cover 15.
0. Outer peripheral surface 31 of the vicinity 75 of the piece member 71
B is beaten with a punch or the like to be caulked to prevent slipping.

A screw provided on the outer periphery of the screw member 72 is screwed into the screw hole 71a of the bridge member 71. Screw member 72
The wrench is engaged with the width across flats provided on the head of the head and rotated. Even when the screw member 72 is loosened, it does not come off by hitting the upper surface of the piece member 71.

At the time of bleeding air, by attaching a vinyl tube TB or the like to the outer periphery of the head of the screw member 72 or inside the hole 73, oil discharged together with air is collected by the vinyl tube TB. can do.

In the embodiment described above, the partition 3
Although the throttle valve 51 and the air vent valve 52 are provided in 6b, they may be provided in other partition portions 36a and 36c. Also,
The partition walls 36a, 36b and 36c may be provided.
The throttle valve 51 and the air release valve 52 are separated from each other by a partition wall portion 36.
a, 36b, and 36c.

In the embodiment described above, three partition portions 36a, 36b, 36c and the like are provided, but one or two partition portions may be provided. In the embodiment described above,
Expansion holes 34a, 34b, 34c, throttle passage hole 35
The shape, size, position, number, etc. of the a, 35b, 35c, the partition walls 36a, 36b, 36c, etc. can be variously changed.

In the above embodiment, the head cover 15 shown in FIG. 10 has been described.
Can be similarly applied. In that case,
Since the piston rod passes through the rod cover 14, the cushion hole 34 becomes a through hole.

Either the rod cover 14 or the head cover 15 described above, or both, can be applied to the hydraulic cylinder 1. In addition, the configuration, shape, dimensions, material, and the like of the entire or each part of the fluid pressure cylinder 1, the rod cover 14, or the head cover 15 may be various other than those described above in accordance with the gist of the present invention.

[0046]

According to the present invention, the flow resistance of the throttle flow path can be reduced as much as possible to reduce the variation in the cushion effect and to reduce the manufacturing cost.

[Brief description of the drawings]

FIG. 1 is a sectional side view of a head cover according to the present invention.

FIG. 2 is a front view of the head cover of FIG. 1 as viewed from the direction of arrow II.

FIG. 3 is a sectional view of the head cover of FIG. 1 taken along line III-III.

FIG. 4 is a cross-sectional side view of the head cover before processing.

FIG. 5 is a sectional view of the head cover before processing at the same position as in FIG. 3;

FIG. 6 is a plan view of a throttle valve.

FIG. 7 is a sectional view of a throttle valve.

FIG. 8 is a plan view of a valve for bleeding air.

FIG. 9 is a cross-sectional view of a valve for bleeding air.

FIG. 10 is a sectional view showing a structure of a general fluid pressure cylinder.

[Explanation of symbols]

 Reference Signs List 1 fluid pressure cylinder 11 cylinder tube 12 piston 14, 14B rod cover (cylinder cover) 15, 15B head cover (cylinder cover) 32, 32B inner end surface 34 cushion hole 34k opening 34a, 34b, 34c expansion hole 35a, 35b, 35c Restriction flow passage holes 36a, 36b, 36c Partition wall 37, 37B Recessed groove 38 Communication hole 39 Valve hole 40 Air vent hole 43 Port hole 51 Throttle valve 52 Air vent valve PT2 port (port hole)

Claims (9)

[Claims] 1. A cylinder cover for closing an end surface of a cylinder tube used for a fluid pressure cylinder, wherein the cylinder cover slides on an inner peripheral surface of the cylinder tube so as to open to an inner end surface facing a cylinder chamber. A cushion hole in which a cushion boss provided in the piston is inserted, and a throttle channel hole adjacent to the cushion hole and the partition wall are provided. The cushion hole is a portion facing the partition wall inside the cushion hole. An expansion hole is provided at a position radially wider than the opening of the cushion hole, so that the thickness of the partition wall is reduced by the opening of the cushion hole and the opening of the throttle channel hole. A cylinder cover for a fluid pressure cylinder, wherein the cylinder cover is set to be smaller than a distance between the cylinder and the hydraulic cylinder. 2. The cylinder cover is surrounded by four outer peripheral surfaces and has a square shape when viewed from the front. The expansion hole, the partition, and the throttle passage hole are each provided with the three outer peripheral surfaces. The cylinder cover for a fluid pressure cylinder according to claim 1, wherein three positions are provided at positions facing the surface, and another one outer peripheral surface is provided with a port hole communicating with the cushion hole. 3. The cylinder cover for a fluid pressure cylinder according to claim 2, wherein the opening of the throttle passage hole has an arc shape centered on a center position of the cushion hole. 4. A cylinder for a fluid pressure cylinder according to claim 2, wherein said inner end face is provided with a circumferential groove at a position including an opening of said throttle flow path hole. cover. 5. The fluid pressure cylinder according to claim 1, wherein at least one of the partition walls is provided with a communication hole that communicates the cushion hole and the throttle channel hole. Cylinder cover. 6. The valve according to claim 5, wherein an outer peripheral surface facing the partition wall is provided with a valve hole for mounting a throttle valve inserted into the communication hole to adjust the throttle amount. Cylinder cover for fluid pressure cylinder. 7. The fluid pressure cylinder according to claim 6, wherein an air vent hole for mounting an air vent valve in communication with the throttle channel hole is provided in parallel with the valve hole. Cylinder cover. 8. The cylinder cover for a hydraulic cylinder according to claim 1, wherein the cylinder cover is formed by casting. 9. A fluid pressure cylinder assembled using the cylinder cover according to claim 1.