JP2556599Y2 - Remote control valve operating rod positioning mechanism - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a positioning device for a control rod such as a lever or a pedal of a remote control valve having a stepless detent function, which is used for spool control of a directional flow control valve and tilt control of a variable pump. .

[0002]

2. Description of the Related Art Conventionally, for example, Japanese Utility Model Publication No. 55-330
No. 41 discloses a technique of using a remote control valve for adjusting the tilt angle of an axial piston pump or the like. FIG. 8 shows an example of an operating rod positioning mechanism in a conventional remote control valve.

The operation handle 1 is fixed to a handle pin 2 via a bush 3. One end of the bush 3 is pressed by nuts 4 and 5. The other end of the bush 3
It comes into contact with the cover 8 via the disc spring 6 and the washer 7. Due to the elastic force of the disc spring 6, the handle pin 2
Is biased to the right. For this reason, a frictional force is generated in the friction portion 9, and the operation handle 1 is operated to operate the operation handle 1.
Is released, it can be held in its operating position.

An arm 10 is fixed to the other end of the handle pin 2. A recess 11 is formed at one end on the outer periphery of the arm 10. When the steel ball 12 fits into the recess 11 and the steel ball 12 also fits into the recess 14 of the holder 13, the operation handle 1 constitutes a detent mechanism in which the operation handle 1 is in the neutral position.
When the operation handle 1 is angularly displaced to operate at an angle different from the neutral position, the operation handle 1 is held by the frictional force of the friction portion 9. The angular displacement of the arm 10 due to the operation of the operation handle 1 is performed to adjust the secondary pressure of the pressure reducing valve via the push rod 15. Push rod 15 is plug 1
6 is inserted. As described above, the operation handle 1 has the detent function in which the steel ball 12 fits into the recesses 11 and 14 at the neutral position, and can adjust the secondary pressure steplessly.

[0005]

The positioning mechanism as shown in FIG. 8 uses a holding torque for giving the operation handle 1 a stepless detent function to the friction portion 9 of the handle pin 2.
Directly generated by the frictional force at Friction part 9
Has a small torque radius from the axis of the handle pin 2.
Further, since this frictional force is generated by the spring force of the disc spring 6, it is necessary to increase the spring constant of the disc spring 6 in order to increase the frictional force.

[0006] However, since the torque radius of the friction portion 9 is small, the contact area is small, and if the frictional force is to be increased, the surface pressure becomes excessive and durability and reliability are poor. Further, the spring constant of the disc spring 6 becomes excessive, and it becomes difficult to finely adjust the holding torque of the operation handle 1, resulting in poor operability. In addition, the fluctuation of the holding torque due to set or wear due to excessive spring constant of the disc spring 6 becomes large, and the maintainability is deteriorated.

An object of the present invention is to provide an operation rod positioning mechanism for a remote control valve which can reduce the surface pressure of a friction portion and has high durability and reliability.

[0008]

SUMMARY OF THE INVENTION According to the present invention, there is provided an operation rod positioning mechanism for a remote control valve for oscillatingly displacing an operation rod and performing control corresponding to the amount of displacement. A sliding member having a sliding surface formed at a distance radially outward from the swing shaft, and a distal end abutting on the sliding surface of the sliding member, and the spring is biased inward in the radial direction. And an operating rod positioning mechanism for the remote control valve.

In the present invention, a V-shaped groove is formed on the sliding surface, and a tip of the pressing member is formed so as to fit into the V-shaped groove.

The pressing member according to the present invention is characterized in that a recess for filling a lubricant is formed on a surface of a tip portion of the pressing member.

[0011]

According to the present invention, the sliding member is swingably displaced integrally with the operating rod. A sliding surface is formed on the sliding member at an interval outward in the radial direction of the swing shaft. The tip of a pressing member that is spring-biased inward in the radial direction contacts the sliding surface. The sliding surface is pressed by the tip of the pressing member, and a frictional force is generated. Since the sliding surface is formed at an interval radially outward from the swing shaft, even if the pressing force is reduced to lower the surface pressure, the friction torque increases. This enables highly durable and highly reliable positioning.

According to the present invention, a V-shaped groove is formed on the sliding surface, and the tip of the pressing member is fitted into the V-shaped groove. Thereby, the contact area between the sliding surface and the pressing member is increased, and the surface pressure can be reduced. Further, a large frictional force can be obtained with a small spring bias due to the frictional effect of the wedge.

According to the present invention, a recess for filling the lubricant is formed on the surface of the distal end portion of the pressing member. When the recess is filled with the lubricant, the sliding portion can be lubricated for a long period of time, the swinging displacement of the operating rod can be performed smoothly, and the reliability is improved.

[0014]

1 and 2 show a schematic configuration of an embodiment of the present invention. FIG. 1 is a cross-sectional view as viewed from a direction perpendicular to the swing axis of the operating rod, and FIG. 2 is a cross-sectional view as viewed from a section line II-II in FIG.

An operating handle 21 as an operating rod is constituted by a handle bar 22 and a grip ball 23 screwed to the tip thereof. The other end of the handlebar 22 is screwed to a lever 24. The lever 24 is attached to a disk 26 which is a sliding member by a bolt 25. The disk 26 is fixed to the camshaft 2 by a set screw 27.
It is fixed to 8. A lock nut 29 for preventing loosening is provided between the handlebar 22 and the lever 24. The periphery of the lever 24 is covered with a bellow 30 made of a synthetic resin such as PVC. With the above-described configuration, when the operation handle 21 is rocked and displaced with the cam shaft 28 as the rocking axis, the disk 26 is also rocked and displaced integrally.

The cam shaft 28 is supported by the upper cover 31. On the lower surface of the disk 26, a pair of push rods 3
5 comes into contact. The push rod 35 is connected to the spring chamber 3.
4 is inserted into a pair of plugs 36 attached to the upper part of the plug 4. A port plate 37 is attached to a lower portion of the casing 33 by bolts 38. A bush 39 is inserted into the lower center of the casing 33.

Below the push rod 35, a pair of spools 40 are arranged. Above each spool 40,
Springs 41 and 42 are arranged. The outer spring 41 has a diameter larger than the outer diameter of the spool 40, and the lower end thereof contacts the inner surface of the spring chamber 34. Inner spring 4
The lower end of 2 is in contact with the upper spring receiving surface of spool 40. The upper ends of the springs 41 and 42 abut on a pair of spring seats 43. The upper surface of each spring seat 43
It contacts the upper end of the spool 40 via the washer 44.
A washer 45 is also provided between the spring receiving surface of the spool 40 and the lower end of the spring 42. Push rod 3
The space between the plug 5 and the plug 36 is sealed by a seal 46 so as to be insertable. Between the plug 36 and the casing 33,
It is hermetically sealed by an O-ring 47. Casing 3
An O-ring 48 for hermetic sealing is also provided between the port 3 and the port plate 37. A bush 49 is provided between the upper cover 31 and the cam shaft 28. Grease is applied to each sliding portion.

The disk 26 is pressed from one side by a holder 50 which is a pressing member. The holder 50 can be inserted through the friction plug 51. The inner end of the friction plug 51 is screwed to the upper cover 31. The pressing force of the spring 53 acts on the outer end of the holder 50 via the washer 52. The other end of the spring 53 is pressed by an adjusting nut 54 screwed to the outer end of the friction plug 51. This pressing force can be changed by changing the position of the adjustment nut 54. When the adjustment is completed, the adjustment nut 54 is stopped and held by using the lock nut 55.

A holder 60 is provided on the side of the disk 26 facing the holder 50. Holder 60
Can be inserted through the detent plug 61. A steel ball 62 is held at a tip on the inner end side of the holder 60, and the steel ball 62 contacts the outer peripheral surface of the disk 26. The outer end of the holder 60 contacts one end of the spring 64 via the washer 63. The other end of the spring 64 is
Pressed by. The adjustment nut 65 can adjust the pressing force of the spring 64, similarly to the above-described adjustment nut 54, and is held by the lock nut 66.

In the casing 33, a pair of spools 40
Form a first pressure reducing valve 71 and a second pressure reducing valve 72, respectively. In the first pressure reducing valve 71 and the second pressure reducing valve 72, the spool 40 is connected to the push rod 3 via the spring 42.
5 is pressed downward. 1 and 2 show a state where the operation handle 21 is in a neutral position. In this state,
In each of the first pressure reducing valve 71 and the second pressure reducing valve 72, a secondary port formed in the port plate 37 is electrically connected to the discharge port T. When the operating handle 21 is oscillated and one push rod 35 is pushed down by the lower surface of the disk 26, the spool 40 below the pushed down push rod 35 is also pushed down via the spring 42. When the spool 40 is depressed, the pressure reducing port 2 of one of the pressure reducing valves formed by the
Pressure oil flows out to the next port. This pressure increases in accordance with the force pressed by the spring 42, that is, the operation angle of the operation handle 21.

FIGS. 3, 4 and 5 show configurations relating to the disk 26 and the holder 50 of FIG. 1, respectively.
3 shows the shape of the disk 26, FIG. 4 shows the shape of the holder 50,
FIG. 5 shows a sliding state between the disk 26 and the holder 50, respectively. 3A is a plan view of the disk 26, and FIG. 3B is a front view of the disk 26. FIG.
(1) is a plan view of the holder 25, and FIG.
4 (3) shows a view from the direction of the arrow 78 in FIG. 4 (1).

Referring to the above figures, the disk 26 has a sliding surface formed radially outward of the camshaft 28 shown in FIGS. 1 and 2, and one of the sliding surfaces has a V-shaped groove 75. Is provided. A notch 76 corresponding to the neutral position is provided on the other sliding surface. The shape of the disk 26 should be such that the disk should be parallel to the parallel 2 so that the distance between the sliding surface and the camshaft is as large as possible.
It has a shape cut in a plane, and the remaining circumferential surface is used as a sliding surface.

The tip portion 77 of the holder 50 has a recess 79
Is formed. The recess 79 can be filled with a lubricant such as grease. The distal end portion 77 of the holder 50 is pressed inward in the radial direction while being fitted in the V-shaped groove 75 of the disk 26. Since the area of the sliding surface is large,
Even if the load per unit area, that is, the surface pressure is small, a large frictional force can be generated. And the sliding surface is
Since the distance from the camshaft 28 is large, a large friction torque can be generated. In addition, a recess 7
Since lubricant such as grease is supplied from 9, the operation handle 21 can be smoothly displaced when the operation handle 21 is operated.

FIG. 6 shows the relationship between the operation angle of the operation handle 21 and the secondary pressure at each port of the port plate 37.
The operation handle 21 is, for example, ±
Displacement up to 20 degrees is possible. The secondary pressure is set according to the operation angle. Disc 26 and tip 7 of holder 50
By means of the sliding friction according to 7, it is possible to hold at any operating angle and to derive a corresponding secondary pressure. Using this pressure, for example, spool control of the directional flow control valve, tilt control of the variable pump, and the like can be performed. When the operation handle 21 is moved, since the recess 79 is filled with the lubricant such as grease as described above, a smooth operation can be performed for a long period of time.

FIG. 7 shows an equivalent hydraulic circuit of the embodiment shown in FIGS. The secondary pressure of the first pressure reducing valve 71 and the second pressure reducing valve 72 is adjusted by the pressing force of the inner spring 42. The spring 42 is connected to the operation handle 2.
The pressing force changes according to the operation angle of 1. The outer spring 41 works for return.

The disk 26, holders 50 and 60,
The steel ball 62 uses a hard alloy steel in consideration of wear resistance. Although the operating handle 21 is used as the operating rod, another lever, pedal, or the like may be used, and the same effect is achieved. Although the detent mechanism using the steel ball 62 operates only at the neutral position, it can operate at a plurality of positions including other angles.

[0027]

As described above, according to the present invention, the frictional force for holding the operating rod is provided by the sliding friction on the sliding surface formed radially outward from the swing shaft. In addition, a large holding torque can be generated even when the surface pressure of the sliding surface is small. Since the surface pressure of the sliding portion is reduced, wear on the sliding surface is reduced, and durability and reliability are improved. Also, the spring constant of the spring pressing the pressing member can be reduced, and fine adjustment of the holding torque by adjusting the spring constant or the like is easy. Further, the spring is less likely to be set, and the fluctuation of the holding torque is reduced.

According to the present invention, the contact area between the sliding surface and the tip of the pressing member is increased, and the surface pressure can be further reduced. Thereby, the durability and reliability of the sliding surface are increased.

According to the present invention, since the recess for filling the lubricant is formed on the surface of the tip portion of the pressing member, the recess is filled with the lubricant and the sliding surface is provided for a long time. Lubrication can be performed. Thereby, wear of the sliding surface is reduced, and operability and durability are also improved.

[Brief description of the drawings]

FIG. 1 is a sectional view of an embodiment of the present invention.

FIG. 2 is a cross-sectional view taken along the line II-II shown in FIG.

FIG. 3 is a plan view and a front view of the disk 26 of FIG. 1;

FIG. 4 is a plan view, a front view, and an arrow view of the holder 50 of FIG. 1;

5 is a view showing a sliding state between the disk 26 and the holder 50 in FIG.

FIG. 6 shows the operation angle and 2 of the operation handle 21 of the embodiment of FIG.
It is a graph which shows the relationship with a next pressure.

FIG. 7 is an equivalent hydraulic circuit diagram of the embodiment of FIG.

FIG. 8 is a sectional view showing a positioning mechanism according to the prior art.

[Explanation of symbols]

 Reference Signs List 21 operation handle 24 lever 26 disk 28 cam shaft 31 upper cover 33 casing 34 spring chamber 35 push rod 36 plug 37 port plate 40 spool 41, 42 spring 43 spring seat 50, 60 holder 53, 64 spring 54, 65 adjusting nut 62 steel Sphere 71 first pressure reducing valve 72 second pressure reducing valve 75 V-shaped groove 76 notch 77 tip 79 recess

Claims (3)

(57) [Scope of request for utility model registration] An operation rod positioning mechanism for a remote control valve for oscillating an operation rod and performing control corresponding to the amount of displacement, wherein the operation rod is oscillated integrally with the operation rod and radially outward from the oscillating shaft. A sliding member having a sliding surface formed at an interval to the sliding member, and a pressing member having a tip abutting on the sliding surface of the sliding member and being spring-biased inward in the radial direction. Features a remote control valve operating rod positioning mechanism. 2. A V-shaped groove is formed on the sliding surface,
The operating rod positioning mechanism for a remote control valve according to claim 1, wherein a tip of the pressing member is formed so as to fit into the V-shaped groove. 3. A concave portion for filling a lubricant is formed in a surface of a front end portion of the pressing member.
Or the operating rod positioning mechanism of the remote control valve according to claim 2.