JPH102304A - Hydraulic cylinder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hydraulic cylinder to perform accurate operation through the blocking of deformation of a packing member, being abundant in a pressure resistance and light in weight and besides low in a manufacturing cost. SOLUTION: A hydraulic cylinder 40 is provided with a cylinder body 42 formed of aluminum and an aluminum alloy and a hole part 48 in a circular shape in cross section is formed in the cylinder body 42. A cylindrical member 50 which is formed of a material, such as a carbon steel and stainless, having a high strength, and on which a pressure of hydraulic oil is exerted is inserted in the hole part 48. A piston 56 is axially slidably disposed at the inside of the cylindrical member 50. A pair of wearing rings 62a and 62b are arranged on the outer periphery of the piston 56 and a packing member 64 is located between the wearing rings 62a and 62b. A first cover member 82 is arranged at one end part of the cylinder body 42 and a second cover member 104 at the other end part. Feed oil holes 94 and 112 communicated through an outer wall with the interior of the cylindrical member 50 are formed in cover members 82 and 104, respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic cylinder in which a piston slides with a fluid such as pressure oil.

[0002]

2. Description of the Related Art A hydraulic cylinder according to the prior art is shown in FIG.
And FIG. The fluid pressure cylinder 10 has a cylinder body 12 formed of a material such as aluminum by extrusion or the like. The cylinder body 12 has a hole 14 having a circular cross section. The hole 16 has a piston 16
Is slidably inserted in the axial direction, and separates the hole portion 14 into one chamber 18a and the other chamber 18b. A groove 19 is formed in the outer circumference of the piston 16 along the circumferential direction, and the packing member 2 formed in an annular shape is formed in the groove 19.
1 is attached. The packing member 21 prevents the pressurized fluid from leaking between the chambers 18a and 18b. Further, the packing member 2 is attached to the piston 16.
An annular wear ring 23 is provided on the outer circumference of the piston 16 at a distance from the piston 1, and a piston rod 20 is fixed to one end of the piston 16 so as to extend in the axial direction of the piston 16.

A female screw 22a is provided in the opening of the hole 14,
22b is engraved, and the female screws 22a and 22b are
The closing members 26a and 26b formed with 4a and 24b are screwed into the holes 14 to close the holes 14. In this case, a hole 28 is defined in one closing member 26a, and the piston rod 20 is slidably inserted into the hole 28. Holes 30a, 30b for supplying pressure fluid are formed in the cylinder body 12 to communicate with the chambers 18a, 18b from a predetermined surface of an outer wall of the cylinder body 12, respectively. The air vent holes 32a, 32b having a smaller diameter than the holes 30a, 30b are provided in the chambers 18a, 18b.
b are provided so as to communicate with each other.

In this hydraulic cylinder 10, one of the holes 3
From 0b, a pressurized fluid, for example, pressurized oil is introduced into one chamber 18b, and presses the piston 16. Therefore, the room 18a
Is discharged through the hole 30a, and the piston 16 slides in the direction of arrow A. On the other hand, when the piston 16 is slid in the direction of arrow B, pressure oil may be introduced into the chamber 18a from the hole 30a and discharged from the chamber 18b through the hole 30b.

[0005]

In recent years, there has been a tendency to increase the pressure of pressurized oil in order to make equipment using the hydraulic cylinder 10 compact. However, in the fluid pressure cylinder 10 according to the related art, since the cylinder body 12 is formed of a material such as aluminum, there is a concern that it cannot withstand high pressure. Therefore, the cylinder body 12
Although a fluid pressure cylinder 10 formed of a strong material such as carbon steel or stainless steel itself has been developed, such a cylinder body 12 is difficult to cut.
There is a disadvantage that the manufacturing cost increases and the weight of the hydraulic cylinder 10 increases, so that the strength of equipment using the hydraulic cylinder 10 must be increased.

When the pressure of the pressurized oil is applied to one of the chambers 18a or 18b, the packing member 21
Enters the slight gap between the outer periphery of the piston 16 and the wall forming the hole 14, and the packing member 21 deforms to
The problem that pressure oil leaks between a and 18b is exposed.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to prevent deformation of a packing member in a hydraulic cylinder to prevent leakage of pressurized fluid from one chamber to another chamber. , Pressure-resistant and lightweight,
Moreover, it is an object of the present invention to provide a hydraulic cylinder having a low manufacturing cost.

[0008]

In order to achieve the above object, the present invention provides a cylinder body and a cylindrical member inserted into a hole defined in the cylinder body and receiving a pressure of a pressurized fluid. A piston slidably provided inside the cylindrical member, wherein the piston slides by the pressure of the pressure fluid introduced into the cylindrical member.

According to the present invention, the pressure fluid is introduced into the cylindrical member, and the piston slides in the cylindrical member in the axial direction. At this time, since the pressure of the pressure oil is applied to the cylindrical member, there is no fear that the cylinder body is damaged.

In this case, it is preferable that the tubular member be made of carbon steel or stainless steel because the strength of the tubular member is increased.

In this case, it is preferable that the cylinder body is made of aluminum or an aluminum alloy, since the fluid pressure cylinder can be made lightweight.

Further, the present invention provides a pair of wear rings provided on the outer periphery of the piston and separated by a predetermined distance.
A packing member provided within an interval between the pair of wear rings.

According to this structure, the packing member is sandwiched between the pair of wear rings, and the packing member prevents the packing member from entering the gap between the piston and the cylindrical member. Therefore, there is no concern that the packing member is deformed and the pressure fluid leaks, which is preferable.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A hydraulic cylinder according to the present invention will be described in detail below with reference to the accompanying drawings showing preferred embodiments.

In FIG. 1 and FIG.
Shows a fluid pressure cylinder according to the present embodiment. The fluid pressure cylinder 40 has a substantially rectangular parallelepiped cylinder body 4.
The cylinder body 42 is extruded from a material such as aluminum or aluminum alloy. As shown in FIG. 3, a plurality of grooves 44 for mounting a piston position detecting sensor (not shown) are defined on each surface of the outer wall of the cylinder body 42. Holes 46a to 46d are defined near the corners of the cylinder body 42, so that the outer wall of the cylinder body 42 is formed to be thin, and the cylinder body 42 is reduced in weight. A hole 48 having a circular cross section is defined at the center of the cylinder body 42, and the hole 48 is isolated from the holes 46a to 46d by walls forming the hole 48. The hole 4
A cylindrical member 50 made of a high-strength material such as carbon steel or stainless steel is inserted into the portion 8. As shown in FIG. 4, a thin portion 52 is formed at one end of the tubular member 50, and the thin portion 52 protrudes from one opening of the hole 48.

A piston 56 is provided inside the cylindrical member 50.
Are slidably inserted in the axial direction, and the cylindrical member 5
0 is separated into one chamber 58a and the other chamber 58b. A groove 60 is defined on the outer periphery of the piston 56 along the circumferential direction, and a pair of wear rings 62a, 62b formed in an annular shape and having an L-shaped cross section are provided in the groove 60 at predetermined intervals. Can be The wear ring 62a
A packing member 64 is provided in the gap between the outer ring 62b and the outer ring 62b, and the packing member 64 is sandwiched between the wear rings 62a and 62b. The packing member 64 prevents pressure oil from leaking between the chamber 58a and the chamber 58b. A ring-shaped position detecting magnet 66 is provided on the outer periphery of one end of the piston 56. The magnet 66 is sandwiched and fixed to the piston 56 by a circular plate-shaped member 68.

At the center of the piston 56, a hole 70 having an internal thread is formed along the axial direction of the piston 56, and a male screw 74 formed at one end of the piston rod 72 is formed in the hole 70. Screw in. Therefore, the piston rod 72 is coaxially fixed to the piston 56. A slightly reduced diameter portion 76 is formed on the other end side of the piston rod 72, and flat portions 78a and 78b are formed in the reduced diameter portion 76 at positions symmetrical with respect to the center line of the piston rod 72. Is done.
At the end of the piston rod 72, a hole 80 having an internal thread is formed along the axial direction thereof, and a device driven by the hydraulic cylinder 40 is fixed to the internal thread of the hole 80. .

At one end of the cylinder body 42, a first cover member 82 made of an aluminum alloy or the like is provided. As shown in FIGS. 2 and 4, the first cover member 82 has a circular recess 84 formed therein.
4 is engaged with the thin portion 52 of the tubular member 50. A groove 86 is defined in the wall forming the recess 84, and an O-ring 88 is fitted into the groove 86. Therefore, the wall of the concave portion 84 and the cylindrical member 50 are
The pressure oil is prevented from leaking from the gap between the pressure oil and the pressure. The bottom of the concave portion 84 is formed with a protrusion 90 slightly projecting in the axial direction, and the end of the piston 56 abuts on the protrusion 90 to position the piston 56.

The first cover member 82 has an oil supply hole 94 formed with an internal thread communicating with the chamber 58b from the outer wall of the first cover member 82, and a pipe joint (not shown) is formed in the oil supply hole 94. Are configured to be freely fastened. In the first cover member 82, an air vent hole 98 having a diameter smaller than that of the oil supply hole 94 and provided with a female screw is defined so as to communicate with the concave portion 84 (see FIG. 2). Screw into the female screw.

As shown in FIG. 2, holes 100a to 100d are defined in the vicinity of the corners of the first cover member 82, and female screws are provided near and parallel to the holes 100a to 100d. Are formed in the holes 102a to 102d. The holes 100a to 100d and the holes 102a to 102d communicate with the holes 46a to 46d of the cylinder body 42.

A second cover member 104 made of an aluminum alloy or the like is provided at the other end of the cylinder body 42.
As shown in FIG. 4, the second cover member 104 has a protrusion 106 that fits inside the tubular member 50.
Are formed. An annular groove 108 is defined on the outer periphery of the protrusion 106, and an O-ring 110 is formed in the groove 108.
Are fitted. The O-ring 110 prevents pressure oil from leaking from inside the tubular member 50.

The second cover member 104 is provided with an oil supply hole 112 which communicates with the chamber 58a from the outer wall of the second cover member 104 and has a female screw. Further, the second cover member 104 is formed with an air vent hole 114 having a smaller diameter than the oil supply hole 112 and formed with a female screw like the air vent hole 98 so as to communicate with the chamber 58a.

At the center of the second cover member 104,
As shown in FIG. 2, a hole 116 is defined and the hole 11
6, the piston rod 72 can be inserted freely. Two annular grooves 118a and 118b are engraved on the wall forming the hole 116 along the circumferential direction thereof.
The packing members 120a and 120b are fitted to 18a and 118b. The packing members 120a and 120b are in sliding contact with the outer peripheral wall of the piston rod 72, and prevent pressure oil from leaking from a gap between the piston rod 72 and the wall of the hole 116. A bush 122 is provided on the wall of the hole 116 so that the piston rod 72 can slide on the wall of the hole 116 with a small resistance.

In the vicinity of the corner of the second cover member 104, holes 124a to 124d corresponding to the holes 100a to 100d of the first cover member 82 are provided. In the vicinity of the holes 124a to 124d, U-shaped steps 126a to 126d are provided which are deviated from the holes 124a to 124d by a predetermined angle with respect to the center line C, and the steps 126a to 126d are provided.
Holes 128a to 128d corresponding to the holes 102a to 102d are provided inside 26d. The hole 12
The holes 4a to 124d and the holes 128a to 128d communicate with the holes 46a to 46d of the cylinder body 42. The holes 128a to 128d have screws 130a to 1
30d is inserted, and the distal end thereof is inserted through the holes 102a-102 through the holes 46a-46d of the cylinder body 42.
Enters d and is concluded. For this reason, the first cover member 82 and the second cover member 104
2 is firmly fixed.

The hydraulic cylinder 40 according to the present embodiment
Is basically configured as described above, and its operation will be described below.

When the fluid pressure cylinder 40 is provided,
Screws (not shown) into the holes 124a of the second cover member 104
To 124d to the hole portions 46a to 46 of the cylinder block.
d, by passing through the holes 100a to 100d of the first cover member 82, for example, to be fixed to a manufacturing facility or the like (not shown).

When the oil supply holes 94 and 112 are connected to a pressure oil supply via an electromagnetic valve (not shown) and the pressure oil supply is urged to introduce pressure oil into the chambers 58a and 58b, the air vent holes 98 and 112 are opened.
The air in the chambers 58a and 58b is exhausted from 114. After all the air is discharged from the chambers 58a and 58b and the pressure oil is discharged from the air vent holes 98 and 114, the pressure oil supply source is stopped, and the air vent holes 98 and 114 are closed with a plug member (not shown).

After the above preparatory steps, the solenoid valve (not shown) is switched to connect the pressure oil supply source to the oil supply hole 94, and the pressure oil supply source is energized to supply the pressure oil. As shown, pressure oil is introduced into one chamber 58b, and the piston 56 is pressed. Therefore, pressure oil is discharged from the chamber 58a through the oil supply hole 112, and the piston 56 slides inside the tubular member 50 in the direction of arrow D. Accordingly, a device (not shown) connected to the piston rod 72 is displaced in the direction of arrow D. At this time, the pressurized oil is applied to the inner wall of the tubular member 50. However, since the tubular member 50 is formed of high-strength carbon steel, stainless steel, or the like, the tubular member 50 has high pressure resistance and is not likely to be damaged. Further, since the pressure of the pressure oil is not applied to the cylinder body 42, the cylinder body 42 is not damaged.

The pressure of the pressure oil is also applied to the packing member 64 so as to deform the packing member 64 toward the chamber 58a.
Since it is supported by a and 62b, it does not deform and is prevented from entering the gap between the piston 56 and the inner wall of the tubular member 50. Therefore, there is no concern that pressure oil leaks between the chambers 58a and 58b.

Next, when a pressure oil is supplied to the oil supply hole 112 by switching an electromagnetic valve (not shown), the pressure oil is introduced into the chamber 58a to press the piston 56, and the pressure oil is supplied from the chamber 58b through the oil supply hole 94. After being discharged, the piston 56 slides in the direction of arrow E. Also at this time, the pressure of the pressure oil is applied to the inner wall of the tubular member 50, but there is no concern that the tubular member 50 will be damaged in the same manner as described above. In addition, similarly to the above, since the packing member 64 is prevented from being deformed by the wear rings 62a and 62b, there is no fear that the pressure oil leaks from one chamber 58a to the other chamber 58b. Therefore, a very accurate reciprocating operation is performed.

[0031]

According to the hydraulic cylinder according to the present invention,
The following effects and advantages can be obtained.

Since the cylindrical member to which the pressure of the pressurized oil is applied is made of a high-strength material, the fluid pressure cylinder has high pressure resistance, and the pressure of the pressurized oil is not applied to the cylinder body. Can be formed of a material that is lightweight and easy to process, the weight of the fluid pressure cylinder can be reduced, and the manufacturing cost can be reduced.

Further, since the deformation of the packing member is prevented by the pair of wear rings, there is no fear that the pressure oil leaks from one chamber to the other chamber, and accurate reciprocating operation as a fluid pressure cylinder is performed.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a hydraulic cylinder according to an embodiment of the present invention.

FIG. 2 is an exploded perspective view of the hydraulic cylinder of FIG.

FIG. 3 is a sectional view of the fluid pressure cylinder of FIG. 1 taken along line III-III.

FIG. 4 is a sectional view taken along line IV-IV of the hydraulic cylinder of FIG. 1;

FIG. 5 is a perspective view of a hydraulic cylinder according to the related art.

FIG. 6 is a longitudinal sectional view of the hydraulic cylinder of FIG.

[Explanation of symbols]

40 ... fluid pressure cylinder 42 ... cylinder body 50 ... cylindrical member 56 ... piston 58a, 58b ... chamber 62a, 62b ... wear ring 64, 120a, 120b ... packing member 72 ... piston rod 82, 104 ... cover member 94, 112 ... Oil supply hole

Claims (4)

[Claims] 1. A cylinder body, a cylindrical member inserted into a hole defined in the cylinder body and receiving a pressure of a pressure fluid, and a piston slidably provided inside the cylindrical member. A hydraulic cylinder, characterized in that the piston slides by the pressure of the pressurized fluid introduced into the cylindrical member. 2. The hydraulic cylinder according to claim 1, wherein said tubular member is made of carbon steel or stainless steel. 3. The hydraulic cylinder according to claim 1, wherein the cylinder body is formed of aluminum or an aluminum alloy. 4. The fluid pressure cylinder according to claim 1, wherein a pair of wear rings provided on an outer periphery of the piston and separated by a predetermined distance, and a separation distance between the pair of wear rings. A fluid pressure cylinder, comprising: a packing member provided therein.