JP3493338B2 - Hydraulic operation valve - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulically operated valve which is used in, for example, a construction machine and which remotely controls various actuators by tilting operation of an operating lever.

[0002]

2. Description of the Related Art An operator rides on a construction machine such as a crawler crane to raise and lower a winch or boom and to drive a vehicle body. For example, a boom of such a construction machine is steered by operating a hydraulically operated valve and remotely controlling an actuator that drives the boom. Since the actuator is driven by hydraulic oil and it takes some time for the boom to move up and down, the hydraulic operating valve that controls the supply of hydraulic oil is equipped with a holding mechanism for holding the operating lever in the operating position. The operator's operability and workability are improved.

FIG. 7 is a sectional view showing a conventional hydraulically operated valve 1 having a holding mechanism as described above, and FIG.
FIG. 6 is a cross-sectional view showing the vicinity of a cam disk in a tilted state.
The hydraulic operation valve 1 includes a housing 2, a cam disk 3 tiltably supported by the housing 2, and first and second spools 4 and 5 provided in the housing 2 and displaced by tilting of the cam disk 3. Have. A pump port 6 and a tank port 7 are formed in the housing 2, and a first output port 8 corresponding to the first spool 4 and a second port 9 corresponding to the second output spool 5 are formed in the housing 2. It

When the operating lever 10 is operated in the direction of the arrow A1 to tilt the cam disk 3 from the neutral position shown in FIG. 7 as shown in FIG. 8, the first spool 4 is displaced and the pump port 6 is removed. The first output port 8 communicates with the first
2 corresponding to the operation amount of the operating lever 10 on the output port 8 of
Secondary pressure is generated. On the contrary, move the operating lever 10 to the arrow A2
Direction to tilt the cam disk 3
The spool 5 is displaced so that the pump port 6 and the second output port 9 communicate with each other, and a secondary pressure corresponding to the operation amount of the operation lever 10 is generated in the second output port 9.

First and second return springs 11 and 12 are provided in the housing 2. First return spring 1
1 is a cam disc 2 which is tilted as shown in FIG.
To the neutral position. The second return spring 12 gives a spring force for returning the cam disk 3 tilted in the direction opposite to that of FIG. 8 to the neutral position. By providing such first and second return springs 11 and 12, the cam disk 3 can be returned to the neutral position without the operator having to search for and operate the neutral position.

Further, the housing 2 is provided with a pressing means 13 for pressing the cam disk 3 in order to hold the cam disk 3 at the most tilted position which is most tilted from the neutral position. The pressing means 13 has a steel ball 14 that contacts the outer peripheral surface of the cam disk 3, and a detent spring 15 that presses the steel ball 14 toward the cam disk. Further, the outer peripheral surface of the cam disk 3 with which the steel ball 14 abuts is formed along a cylindrical surface around the tilt axis 16 of the cam disk 3, and when the cam disk 3 is at the most tilted position, A groove 17 into which the steel ball 14 is fitted is formed.

In this hydraulically operated valve 1, when the operating lever 10 is operated, for example, in the direction of arrow A1 to tilt the cam disk 3 from the neutral position to the most tilted position,
The first return spring 11 must be tilted while being compressed, and the operating torque must be applied in the arrow A1 direction. When the cam disk 3 is tilted to the most tilted position in this way, the steel ball 14 fits into the groove 17 to detent (prevent tilting), and the operator returns without operating the operating lever 10 continuously. Springs 11
It is possible to prevent the cam disk 3 from returning from the most tilted position to the neutral position against the spring force of 2 and hold the cam disk 3 at the most tilted position.

In order to return the cam disk 3 held in the most tilted position to the neutral position, the detent must be released, and the operation lever 10 moves the cam disk 3 from the most tilted position to the neutral position. The operating torque must be applied in the direction of arrow A2, which is the direction of returning to the position. When the detent is released by applying this operation torque, even if the operation torque in the direction of returning to the neutral position is not applied to the operation lever 10, the spring force of the first return spring 11 causes the direction of returning to the neutral position. Torque is obtained.

[0009]

FIG. 9 shows a hydraulically operated valve 1.
5 is a graph showing the relationship between the operating angle and the operating torque of the operating lever 10 in FIG. FIG. 9 shows the relationship between the operation angle and the operation torque when tilting from the neutral position to the most tilted position, for example, in the direction of arrow A1 and returning from the most tilted position to the neutral position, and the horizontal axis represents the operation lever 10. The operating angle is shown, and the vertical axis shows the operating torque. The operation torque indicates a positive torque in the direction in which the cam disk 3 tilts the operation lever 10 from the neutral position to the most tilted position.

In the hydraulically operated valve 1, the detent spring 15 that presses the steel ball 14 in order to detent the cam disk 3 at the most tilted position where the first return spring 11 is most deformed and the spring force becomes large, A spring having a high spring constant is used so that a large spring force can be generated even with a small displacement, and when the steel ball 14 is out of the groove 17, the steel ball 14 has a large spring force. The cam disc 3 and the steel ball 1 are pressed and are in contact with the cam disc 3.
A large frictional resistance force is generated between No.4 and No.4. Since the outer peripheral surface of the cam disk 3 is formed along the cylindrical surface, this frictional resistance force is also generated when the cam disk 3 is near the neutral position.

Therefore, as shown in FIG. 9, when it is necessary to increase the holding force for holding the cam disc 3 at the most tilted position beyond the neutral return ability of the first return spring 11, the cam disk 3 is moved to the most tilted position. When the cam is returned to the neutral position after being tilted up to the neutral position, unless the operation torque is applied in the direction of returning the cam disk 3 in the state of returning to the vicinity of the neutral position, the cam does not return to the neutral position and the first return spring Malfunction region 19 for return operation to the neutral position by 11
Will occur. When the operation of returning to the neutral position due to such a return spring is defective, the operation lever 10 is moved to the arrow A2.
Similarly, the return operation by the second return spring 12 when operated in the same direction occurs. Moreover, such a hydraulic operation valve 1 is required to be downsized, and it is desired to make the operation lever 10 short and small. In order to make the operating lever 10 short and small in this way, it is necessary to reduce the spring force of the first and second return springs 11 and 12 in order to prevent deterioration of the operability of the operating lever 10.
When the spring force of the first and second return springs 11 and 12 is reduced in this way, the return operation to the neutral position described above tends to be uncertain.

An object of the present invention is to provide a hydraulically operated valve capable of holding the cam member at the most tilted position and not causing a malfunction in the returning operation to the neutral position.

[0013]

The present invention according to claim 1 is tiltably supported between a neutral position and a most tilted position, and has a large tilt angle from the neutral position in the direction of returning to the neutral position. By tilting the cam member, to which a restoring force that increases as it goes, is tilted from the neutral position,
By selectively displacing the two spools, the output port and the pump port corresponding to one of the spools are communicated with each other, and the output port and the tank port corresponding to the other spool are communicated with each other. In a hydraulically operated valve for generating a secondary pressure according to a tilt angle from a neutral position of a cam member at an output port corresponding to one of the spools, it is provided so as to be able to be displaced toward and away from a tilt axis of the cam member. The contact member is contacted in the contact region of the outer peripheral surface of the cam member, and the contact member is pressed toward the tilt axis of the cam member by a pressing force that increases as the contact member separates from the tilt axis of the cam member. And a contact area of the outer peripheral surface of the cam member from the position where the contact member abuts when the cam member is in the neutral position to the most tilted position. When the cam member is in the most tilted position, the contact member is formed along the reference surface where the distance from the tilt axis of the cam member increases as the contact member comes into contact. A hydraulically operated valve having a fitting recess formed therein.

According to the present invention, when the cam member is tilted in one direction from the neutral position, the output port corresponding to one of the two spools communicates with the pump port, and the other of the two spools communicates with the other. The output port corresponding to the spool communicates, and a secondary pressure corresponding to the tilt angle from the neutral position of the cam member is generated in the output port corresponding to one of the spools. On the contrary, when the cam member is tilted from the neutral position to the other direction opposite to the one direction, the different output port and the pump port communicate with each other when tilted in the one direction, and the other output port is Secondary pressure corresponding to the tilting angle from the neutral position of the cam member is generated in the output port different from the case where the cam member is connected and tilted in one direction. In this way, the cam member that displaces the first and second spools is provided with a restoring force that increases in the direction of returning to the neutral position and as the tilt angle from the neutral position increases.

Further, the hydraulically operated valve is provided with a contact member which can be displaced toward and away from the tilt axis of the cam member, and a pressing means for pressing the contact member toward the cam member.
The contact member is contacted in the contact region of the outer peripheral surface of the cam member by the pressing force of the pressing means. The cam member is formed with a fitting recess into which the contact member fits when the cam member is in the most tilted position. As a result, when the cam member is tilted to the most tilted position, the contact member is fitted into the fitting recess while being pressed by the pressing means, and the cam member is neutralized against the restoring force applied to the cam member. It is possible to prevent the cam member from returning to the position, and it is possible to hold the cam member at the most tilted position without applying an operating force to the cam member. Further, in the state where the contact member is separated from the fitting recess, the prevention of the cam member from returning to the neutral position is released.

The pressing force pressing the contact member increases as the contact member moves away from the tilt axis of the cam member. Further, the outer peripheral surface of the contact area of the cam member moves from the position where the contact member contacts when the cam member is in the neutral position to the position where the contact member contacts when the cam member is in the most tilted position. Is formed along a reference plane that increases in distance from the tilt axis of the. As a result, as the cam member becomes closer to the neutral position, the contact member comes closer to the tilt axis of the cam member, and the pressing force by the pressing means becomes smaller. Therefore, as the position of the cam member approaches the neutral position, the frictional resistance force acting between the cam member and the contact member becomes smaller. Further, the pressing force applied to the contact member is applied to the cam member via the contact member, and a part of this pressing force acts in the direction of returning the cam member to the neutral position.

As described above, the cam member can be held at the most tilted position where the restoring force is maximized, and the cam member and the abutting member move closer to the neutral position where the restoring force applied to the cam member decreases. The frictional resistance between them is reduced, and a part of the pressing force causes the cam member to return to the neutral position, so that the cam member can be smoothly and reliably returned to the neutral position by the returning force.

According to a second aspect of the present invention, there is provided another abutting member which is provided so as to be displaceable toward and away from the tilt axis of the cam member and which abuts at another abutment region of the cam member. , The other abutting member is pushed toward the tilting axis of the cam member by the pressing force that increases as the other abutting member moves away from the tilting axis of the cam member.
One pressing means, and another one of the outer peripheral surface of the cam member.
One abutment area when the cam member is in the neutral position
The neutral side area portion near the position where the two abutting members abut,
And a maximum tilting side area portion near the position where the contact member abuts when the cam member is in the maximum tilt position, and each area portion is contacted by another contact member when the cam member is in the maximum tilt position. They are formed along a reference plane in which the distance from the tilt axis of the cam member increases toward the contact position,
The most tilting side area portion is formed so as to be continuous with the neutral side area portion with a step on the side close to the tilting of the cam member.

According to the invention, in the hydraulically operated valve, another contact member which can be displaced toward and away from the tilt axis of the cam member and the other contact member facing the cam member. Another pressing means for pressing is provided,
The other abutting member is abutted at another abutting region on the outer peripheral surface of the cam member. The outer peripheral surface of the other contact area includes a neutral side area portion near the position where the other contact member abuts when the cam member is in the neutral position, and an abutment member when the cam member is in the most tilted position. Has a step portion on the side close to the tilt of the cam member with respect to the neutral side area portion, and the most inclined side area portion is formed so as to be continuous. It

As a result, when the other contact member is pressed, the contact member is formed at this step portion by being locked at the step portion between the most tilting side region portion and the neutral side region portion. The cam member can be prevented from returning to the neutral position against the restoring force applied to the cam member at the position of the cam member, that is, the intermediate position between the neutral position and the most tilted position. The cam member can be held in the intermediate position without applying an operating force to the cam member. Further, in the state where the other contact member is in contact with the most tilted side region portion and is not locked to the step portion, and in the state where the other contact member is in contact with the neutral side region portion, the neutral position is set. Return blocking is canceled.

The pressing force for pressing the other contact member increases as the other contact member moves away from the tilt axis of the cam member. Further, the neutral side area portion and the most tilting side area portion of the cam member increase in distance from the tilt axis of the cam member as the cam member moves to the position where the other contact member abuts when the cam member is in the most tilted position. Each is formed along the reference plane. As the cam member is placed closer to the neutral position, the
The abutting members are close to the tilt axis of the cam member, and the pressing force by the pressing means is reduced. Therefore, as the position of the cam member becomes closer to the neutral position, the frictional resistance force acting between the cam member and the other contact member becomes smaller. The pressing force applied to the other contact member is applied to the cam member, and a part of this pressing force acts in the direction of returning the cam member to the neutral position.

As described above, by providing a mechanism for holding the cam member at the intermediate position in addition to the mechanism for holding the cam member at the most tilted position, the cam member can be held at the most tilted position and returned as described above. By the force, the cam member can be reliably returned to the neutral position, and the cam member can also be held at the intermediate position.

[0023]

1 is a sectional view showing a hydraulically operated valve 30 according to an embodiment of the present invention, and FIG. 2 shows a cam with a cam disk 32 tilted in a first tilt direction B1. FIG. 6 is a cross-sectional view showing the vicinity of the disc 32. Hydraulically operated valve 30
Is an operation valve that controls the supply and discharge of hydraulic oil to and from an actuator that drives a construction machine to operate the construction machine such as a crawler crane, and remotely controls the actuator. It is provided. The hydraulic operation valve 30 includes, for example, a housing 31 fixed to a console in a driver's seat, and a cam disk 32 that is a cam member that is tiltably supported in the housing 31.
Have and. A shaft 33 having a substantially horizontal axis perpendicular to the plane of FIG. 1 is provided on the upper part of the housing 31, and the cam disk 32 is rotated around the substantially horizontal tilt axis (coincident with the axis of the shaft 33) L1 by this shaft 33. It is tiltably supported. The cam disk 32 is between a neutral position 34 shown by a solid line in FIG. 1 and a first most tilted position 35 shown by an imaginary line most tilted in the first tilting direction B1 from the neutral position 34 around the tilting axis L1. Tiltable and neutral position 34
Is tiltable between the neutral position 34 and the second most tilted position 36 indicated by an imaginary line that tilts the most in the second tilting direction B2 opposite to the first tilting direction B1 around the tilting axis L1. The tilt angles from the neutral position 34 of the most tilted positions 35 and 36 are the same. An operating lever 37 is provided on the cam disk 32 so as to project upward, and the operator can tilt the cam disk 32 by operating the operating lever 37. Also the housing 31
A bellows 38 for protecting the internal mechanism is mounted between the operation lever 37 and the upper part of the.

Below the cam disk 32 in the housing 31, there are two spools 40 and 41, which are first and second selectively displaced by tilting of the cam disk 32.
The first and second spools 40, which are held by the housing 31 and are displaceable in the vertical direction coinciding with the axial direction thereof,
41 and the housing 31 allow the first and second two
One spool valve is constructed. A pump port P and a tank port T are formed on the side portions of the housing 31, and a first output port 42 and a second spool 41 corresponding to the first spool 40 are provided on the lower portion of the housing 31. Corresponding second output ports 43 are respectively formed.

First and second push rods 44 and 45 are fitted on the upper portions of the first and second spools 40 and 41, respectively. Further, the first and second spring receiving pieces 4 are provided on top of the first and second spools 40 and 41.
6 and 47 are provided, and the first and second spools 40 and 41 are externally fitted to form a compression coil spring between the spring receiving portion of the housing 41 and the first and second spring receiving pieces 46 and 47. Certain first and second return springs 48, 49
Are provided respectively. The return spring force of the first return spring 48 is given to the first spool 40 and the first push rod 44 from the first spring receiving piece 46, and the first spool 40 and the first push rod 44 are moved upward. Press. The return spring force of the second return spring 49 is given from the second spring receiving piece 47 to the second spool 41 and the second push rod 45, and the second spool 41 and the second push rod 45 are connected. Press upward.

As shown in FIG. 1, the first and second spring receiving pieces 46, 47 are prevented from being displaced by the housing above the position corresponding to the neutral position 34 of the cam disk 32, and the cam disk is prevented. When 32 is in the neutral position, the first and second push rods 44, 45 and the first and second spools 40, 41 are in the upper limit position, respectively. When the cam disk 32 is in the neutral position,
The upper ends of the first and second push rods 44 and 46 are in contact with the cam disk 32. At this time, the pump port P connected to the pump (not shown) and the first
And the second output ports 42, 43 are cut off, and the first and second output ports 42, 43 are shown via a spring chamber 51 in which first and second return springs 48, 49 are provided. It communicates with the tank port T connected to the tank.

In this way, the cam disk 32 moves to the neutral position 3
From the state shown in FIG.
Is operated and the cam disc 32 is operated in the first tilting direction (direction in which the operating lever is tilted to the right in FIG. 1) B1, and is tilted as shown in FIG. One push rod 44 and first
The spring receiving piece 46 of the first spool 40 is pushed down.
Are pushed down via a first spool pressing spring 52 provided between the first spring receiving piece 46 and the first spool 40. When the first spool 40 is pushed down in this way, the first output port 42 is cut off from the tank port T and communicated with the pump port P. The first spool valve including the first spool 40 is
The first output port 42 is configured to generate a secondary pressure according to the tilt angle from the neutral position of the cam disk 32, specifically, in proportion to the tilt angle, and tilts the cam disk 32. As a result, a secondary pressure proportional to the tilt angle is generated at the first output port. When the cam disk 32 is displaced from this state toward the neutral position, the first
The spool 40 and the first push rod 44 are pressed by the first return spring 48 and displaced upward, and when the cam disk 32 returns to the neutral position, the spool 40 and the first push rod 44 return to the upper limit position.

Further, from the state where the cam disk 32 is in the neutral position 34, the operating lever 37 is operated by the operator, and the cam disk 32 is operated in the second tilting direction (direction in which the operating lever is tilted leftward in FIG. 1) B2. Then, when the cam disc 32 is tilted, the second push rod 45 and the second spring receiving piece 47 are pushed down by the cam disk 32, and
The second spool pressing spring 53 is provided between the second spring receiving piece 47 and the second spool 41.
It is pushed down via. When the second spool 41 is pushed down in this manner, the second output port 43
Is blocked from the tank port T and communicated with the pump port P. The second spool valve including the second spool 41 generates a secondary pressure in the second output port 43 according to the tilt angle from the neutral position of the cam disk 32, specifically, in proportion to the tilt angle. The secondary pressure proportional to the tilt angle is generated at the second output port 43 by tilting the cam disk 32. When the cam disk 32 is displaced toward the neutral position 34 from this state, the second spool 41 and the second push rod 45 are pressed by the second return spring 49 and are displaced upward, so that the cam disk 32 becomes neutral. When it returns to the position, it returns to the upper limit position.

Further, the first and second return springs 48, 49
Of the return spring force of the first and second spools 40, 41.
In addition to pressing the first and second push rods 44 and 45 upward, the first and second push rods 44 and 45 are also transmitted to the cam disc 32 to return the cam disc 32 to the neutral position. Press in the direction.
In other words, the cam disk 32 is provided with a return spring force, which is a return force, in the direction of returning to the neutral position by the first and second return springs 48, 49, and this return spring force is applied. It becomes larger as the tilt angle from the neutral position 34 becomes larger. Therefore, when the operation lever 37 is operated, the operator is given a reaction force by the first and second return springs 48, 49 from the operation lever 37, and the reaction force is generated when the cam disk 32 is in the neutral position. Since the operation amount from the position increases as the operation amount increases, the operator can recognize the operation amount from the position corresponding to the neutral position of the cam disk 32 from the reaction force, and can obtain a suitable operation feeling.

The first output port 42 is connected to a first pilot line of a switching valve (not shown) for switching the supply and discharge of hydraulic oil to the actuator of the construction machine, and the second output port 43 is connected to the switching valve. It is connected to the second pilot line. The switching valve is interposed between the actuator and the pump and the tank, and
And by the secondary pressure from the second output ports 42, 43, which causes remote control of the actuator. The actuator may be an actuator that drives any part of the construction machine, for example a hydraulic motor that drives a boom in a crawler crane.

FIG. 3 is an enlarged front view showing the cam disk 32. Referring also to FIG. 1, the cam disk 3
2 has a substantially oval outer shape in a cross section perpendicular to the tilt axis L1 and has upper and lower surfaces 55 and 56 which are parallel to each other and first and second outer peripheral surfaces extending between both ends of the upper and lower surfaces 55 and 56. 57 and 58. The first outer peripheral surface 57 is divided into a plurality of areas 59 to 63. Regions 59 and 60 at both ends in the circumferential direction around the tilt axis L1 are formed on a cylindrical surface centered on the tilt axis L1. Regions 61 and 62 adjacent to the insides of the regions 59 and 60 are convex toward the tilt axis L1 and are formed in a V-shaped surface extending parallel to the tilt axis L1. The inner central region 63 of each of the regions 61 and 62 is formed in a plane parallel to the tilt axis L1 and in a plane 65 orthogonal to the circumferential center 64 of the tilt axis L1.

The second outer peripheral surface 58 is on the side opposite to the first outer peripheral surface 57 with respect to the tilt axis L1 and has a plurality of regions 67.
It is divided into ~ 69,74,77,78. A region 67 at one end in the circumferential direction around the tilt axis L1 on the upper surface 55 side is formed in a cylindrical surface centered on the tilt axis L1. A region 68 adjacent to the inner side of the region 67 and a region 69 at the other end in the circumferential direction on the lower surface 56 side are planes parallel to the tilt axis L1 and are orthogonal to each other at the inner ends 70, 71 in the circumferential direction.
2, 73 are formed in a plane such that the tilt axis L1 is included therein. The central region 74, which is continuous with the step regions 77 and 78 inside each of the regions 68 and 69, is a plane parallel to the tilt axis L1, and the tilt axis L1 is included in the plane 76 orthogonal to the circumferential center 75. Formed on a flat surface. Each step region 77, 78 is a plane parallel to the tilt axis L1 that tilts away from the tilt axis L1 as it approaches the central region 74.

Further, the hydraulic operation valve 30 includes a cam disk 32.
The tilting axis L1 of the cam disk 32 so as to be movable toward and away from the tilt axis L1.
The first rolling element 81 that abuts in the first abutting region 80 on the outer peripheral surface of the And a first detent spring 82, which is a pressing unit that presses the rolling element 81 toward the tilt axis L1.
The first rolling element 81 is made of, for example, a steel ball, and the first detent spring 82 is made of, for example, a compression coil spring. A holding cylinder 83 penetrating in the axial direction is provided in the upper part of the housing 31 facing the cam disk 32 with its axis orthogonal to the tilt axis L1. By this holding cylinder 83, the first rolling element 81 and the first rolling element 81 Detent spring 82
Is held.

An outer screw is formed on the outer peripheral surface of the end portion of the holding cylinder 83 protruding from the housing 31, and a cap nut member 84 is screwed to the holding cylinder 83 so that its position can be adjusted. A nut member 85 for preventing the member 84 from loosening is screwed. A movable piece 86 that can be displaced along the axis of the holding cylinder 83 is provided in the holding cylinder 83. A recess is formed at the end of the movable piece 86 on the cam disk side, and the first rolling element 81 is held by the movable piece 86 in a state of being partially fitted in the recess. The first detent spring 82 is provided between the cap nut member 84 and the movable piece 86, and presses the first rolling element 81 via the movable piece 86 by the detent spring force to move the first rolling element 81. It can be brought into contact with the cam disk 32.

The first contact area 80 of the cam disk 32, with which the first rolling element 81 contacts, has a first outer peripheral surface 57.
A part of the regions 61 and 62 formed on the V-shaped surface of
And a central region 63 formed in a plane. When the cam disk 32 is in the neutral position 34, the first rolling element 81
Comes into contact with the central position 64 of the central region 63 of the first outer peripheral surface 57, and when the cam disk 32 is at the most tilted position 35 in the first tilting direction B1, the first rolling element 81 moves to the first rolling position. The cam disk 32 contacts the area 61 of the outer peripheral surface 57,
When in the most tilted position 36 in the tilting direction B2, the first rolling element 81 is in contact with the region 62 of the first outer peripheral surface 57. The position where the first rolling element 81 abuts when the cam disk 32 is in the most tilted positions 35 and 36 is the area 6
It is determined by the shapes of 1, 62 and the outer diameter of the first rolling element 81. The regions 61 and 62 are adjacent to the regions 59,
63; 60, 63 are recessed toward the tilt axis L1 from the ends near the region, and recessed grooves 87, 88 extending parallel to the axis L1 which is a fitting recess are formed.

Therefore, when the cam disk 32 is in the most tilted positions 35 and 36, the first rolling element 81 is inserted into each groove 8
The cam disk 32 can be fitted in the cam disk 7 and 88 to prevent the cam disk 32 from returning to the neutral position, that is, detent can be performed. In the hydraulically operated valve 30, the first detent that presses the first rolling element 81 in order to detent the cam disk 32 at the most tilted position 35 where the first return spring 48 is most deformed and the spring force becomes large. As the spring 82, a spring having a high spring constant is used so that a large spring force can be generated even with a small displacement.

More specifically, the spring constant is, for example, about 49 to 58.8 N / mm (5 to 6 kgf / mm). Further, when the cam disk 32 is in the neutral position 34, the position 64 against which the first rolling element 81 abuts and the concave grooves 87, 88.
The difference in the distance from the axis L1 at the end of the region 83 continuous with is about 1 mm, and at the neutral position 34, the first rolling element 81 is pressed with a force of about 98 N (10 kg weight), When the rolling element 81 is at the end of the area 63, it is pressed with a force of about 147 N (15 kg weight).
Further, when the first rolling element 81 is fitted in the concave grooves 87 and 89, it is pressed with a force of about 98 N (10 kg weight). By setting in this way, the most tilted position 3
5 and 36 ensure the detent, and the first rolling element 81 and the cam disk 32 near the neutral position 34.
The frictional resistance between and can be reduced.

As described above, the first contact area 80 of the cam disk 32 is located at the position 64 where the first rolling element 81 contacts when the cam disk 32 is at the neutral position 34, and the cam disk 32 is at the most tilted position 35. 36, the cam disk 3 moves toward the position where the first rolling element 81 abuts.
It is formed along the reference plane 89 where the distance from the second tilt axis L1 increases. Further, the cam disc 32 is formed with concave grooves 87 and 88 into which the first rolling elements 81 are fitted when the cam disc 32 is in the most tilted positions 35 and 36, respectively.

Further, the hydraulic operation valve 30 includes a cam disk 32.
Of the second outer peripheral surface, which is another contact area of the outer peripheral surface of the cam disk 32 and is abutted on the second contact area 90 of the second outer peripheral surface of the cam disk 32. The second rolling element 91 and the second rolling element 91 have the tilt axis L1.
The second detent spring 92 that is a pressing unit that presses the second rolling element 91 toward the tilt axis L1 by a detent spring force that is a pressing force that increases as the distance from the second detent spring 92 increases.
Including and The second rolling element 91 is made of, for example, a steel ball, and the second detent spring 92 is made of, for example, a compression coil spring. Cam disc 3 on top of housing 31
2 is a portion different from the portion where the first holding cylinder 83 is provided, specifically, the portion opposite to the portion where the first holding cylinder 83 is provided with respect to the cam disk 32, in the axial direction. A holding cylinder 93 that penetrates through is provided with its axis orthogonal to the tilt axis L1. The holding cylinder 93 holds the second rolling element 91 and the second detent spring 92.

An external thread is formed on the outer peripheral surface of the end portion of the holding cylinder 93 that protrudes from the housing 31, and the cap nut member 94 is screwed to the holding cylinder 93 so that its position can be adjusted. A nut member 95 for locking the member 94 is screwed. A movable piece 96 that can be displaced along the axis of the holding cylinder 93 is provided inside the holding cylinder 93. A recess is formed at the end of the movable piece 96 on the cam disk side, and the second rolling element 91 is held by the movable piece 96 in a state of being partially fitted in the recess. The second detent spring 92 is provided between the cap nut member 94 and the movable piece 96, and presses the second rolling element 91 via the movable piece 96 by the detent spring force, so that the second rolling element 91 is retained. It can be brought into contact with the cam disk 32.

The second contact area 90 of the cam disk 32, with which the second rolling element 91 contacts, has a second outer peripheral surface 58.
Of the areas 68, 77 and 78 and a part of the areas 68 and 69 near the area 74. When the cam disc 32 is in the neutral position 34, the second rolling element 91 contacts the central position 75 of the region 74 of the second outer peripheral surface 58, and the cam disc 32 is in the most tilted position in the first tilting direction B1. When the second rolling element 91 is in the position 35,
Of the second rolling element 9 when the cam disk 32 is in the most tilted position 36 in the second tilting direction B2.
1 is in contact with the position 101 of the region 68 of the second outer peripheral surface 58. The area 74 and the areas 68 and 69 are connected by the step basins 77 and 78, and the second rolling element 91
The cam disk 32 can be locked by the second rolling element 91 in the state where the cam disk 32 is in contact with the step regions 77 and 78.

Thus, the second contact area 90 of the cam disk 32 is an area 74 which is a neutral side area portion near the position 75 with which the second rolling element 91 abuts when the cam disk 32 is in the neutral position 34. And a part of each area 68, 69 which is the most tilting side area portion near the positions 100, 101 with which the second rolling element 91 abuts when the cam disk 32 is at the most tilting positions 35, 36. Areas 74, 68, 69
Is a reference plane 103, 104 in which the distance from the tilt axis L1 of the cam disk 32 increases toward the positions 100, 101 where the second rolling elements 91 abut when the cam disk 32 is in the most tilted positions 35, 36. , 105 respectively. Area 6 including the most tilting area area
8 has a step on the side closer to the tilt axis L1 of the cam disc 32 with respect to the area 74 which is the neutral side area portion, and is continuous in the step flow area 77, and the area 69 including the most tilt side area portion is A step is formed on the side closer to the tilt axis L1 of the cam disk 32 with respect to the area 74 that is the neutral side area, and the step flow area 78 is formed so as to be continuous.

FIG. 4 shows the operating lever 37 of the hydraulic operating valve 30.
5 is a graph showing the relationship between the operation angle and the operation torque. FIG. 4 shows the relationship between the operating angle and the operating torque when the cam disk 32 is tilted from the neutral position 34 to the maximum tilt position 35 in the first tilt direction B1 and then returned from the maximum tilt position 35 to the neutral position 34. , The horizontal axis represents the operating angle of the operating lever 37,
The vertical axis represents the operating torque. The operating angle is the cam disc 32.
The operation torque coincides with the tilt angle from the neutral position 34, and the operation torque indicates a positive torque in the direction in which the cam disk 3 tilts the operation lever 37 from the neutral position to the most tilted position. The operation torque is a torque required to tilt the cam disk 32.

In the hydraulically operated valve 30, when the cam disk 32 is tilted from the neutral position 34 to the most tilted position 35, the operation angle and the operation torque of the operation lever 37 change as indicated by the first line 105 in FIG. Follow Specifically, the preset load of the return spring 48, the first and second rolling elements 8
Due to the frictional resistance force between the cam disks 1, 91 and the cam disk 32, a predetermined operation torque is required to tilt the cam disk 32 from the neutral position 34. Applying this operating torque, neutral position 3
As the cam disk 32 tilts from 4, the operating torque required to resist the return spring force of the first return spring 48 increases. Further, since the regions 63 and 74 are formed as described above, when the cam disk 32 is tilted from the neutral position 34, the first and second detent springs 82 and 92 are compressed and a large detent spring force is applied. Since the first and second rolling elements 81 and 91 are pressed, the frictional resistance between the first and second rolling elements 81 and 91 and the cam disk 32 gradually increases, which also The required operating torque is large.

When the second rolling element 91 is tilted to the position where it abuts on the step region 78, the concave portion 105 of the first line 105 is formed.
As indicated by a, the second rolling element 91 travels from the area 74 through the step area 78 to the area 69, and at this time, the rolling element 91 tries to rotate the cam disk 32 in the most tilting direction by the step area 74. Therefore, the required operating torque is reduced. The cam disk 32 is at an intermediate detent position which is a predetermined intermediate position, that is, the second rolling element 91.
At a position where the abutting portion simultaneously contacts both the step region 78 and the region 69, the operation torque near the intermediate detent position becomes the smallest. This allows the operator to recognize that the cam disk 32 is in the intermediate detent position.

When the cam disk 32 is further tilted from this intermediate detent position toward the most tilted position 35, the operating torque becomes large again. The first rolling element 81 is the area 6
When the first rolling element 81 is tilted to the position where it comes into contact with the first line 105, the first rolling element 81 moves into the area 61 so as to fit into the concave groove 87, as shown by the inclined portion 105b that descends to the right. Since the rolling element 91 tries to rotate the cam disk 32 in the most tilting direction by the step area 74, the required operating torque becomes small. The cam disc 32 requires a strong force to displace the cam disc 32 further away from the neutral position 34 than the most tilted position, and the most tilted position 35, that is, the first rolling element 81 is located in the region 61 of the groove 87. The most tilted position 3 at the position where two points contact
The operation torque near 5 is the smallest. This allows the operator to recognize that the cam disk 32 has reached the maximum tilt position 35. When the operator releases the operating lever 37 in the most tilted position 35, the operation torque becomes 0 without tilting the cam disk 32, and the cam disk 32 is held at the most tilted position. When moving from the neutral position 34 to the most tilting position 35, an operating torque that always goes in the first tilting direction B1 is required.

As described above, when the cam disk 32 in the most tilted position 35 is tilted toward the neutral position 34, that is, returned, the operation angle and the operation torque of the operation lever 37 are as follows.
Follow the transition as shown by the second line 106 in FIG. Specifically, in order to disengage the first rolling element 81 from the concave groove 87, a predetermined operation torque in the second tilting direction B2 is required in a state in which the cam disk 32 does not tilt, and a rightward tilt As indicated by the portion 106b, as the first rolling element 81 separates from the groove 87, the operating torque toward the second tilting direction B2 gradually decreases, and eventually the operating torque toward the first tilting direction B1. Need.
That is, the cam disk 32 is returned to the neutral position 34 by the return spring force of the first return spring 48 even if the operator does not apply the operation torque to the operation lever 37. When the first rolling element 81 has completely left the groove 87 and has moved to the area 63, the first tilting direction B1
It requires the greatest operating torque towards, in other words the greatest return spring force.

When the second rolling element 91 is returned to the position where it abuts the step region 78, the concave portion 106 of the second line 106.
As shown by b, the second rolling element 91 is
, The cam disk 32 is locked by the second rolling element 91, and an operating torque in the second tilting direction B2 is required. This allows the operator to recognize that the intermediate detent position has been reached. At this intermediate detent position, even if the operator releases the operating lever to reduce the operating torque to 0, the cam disk 32
Does not tilt and is held in the intermediate detent position.

As described above, when the cam disk 32 in the intermediate detent position is returned toward the neutral position 34,
The second rolling element 91 is transmitted from the step area 78 to the area 69.
From the second tilting direction B2
The operating torque toward the second tilting direction B2 becomes gradually smaller as the second rolling element 91 approaches the region 74, and eventually the operating torque toward the first tilting direction B1 is required. And That is, even if the operator does not apply the operation torque to the operation lever 37,
The return spring force of the first return spring 48 causes the cam disk 32 to return to the neutral position 34. Second
After the rolling element 91 of No. 3 has moved to the area 74, the neutral position 3
The cam disk 32 is tilted by the return spring force of the first return spring 48 until it returns to 4.

The transition of the operating torque when the cam disk 32 is tilted from the neutral position 34 to the most tilted position 35 has been described with reference to FIG.
When 2 is tilted from the neutral position 34 toward the most tilted position 35 to the intermediate detent position and tilted so as to return from the intermediate detent position to the neutral position 34, after tilting to the intermediate detent position, the virtual Line 107
In the state where the tilting position of the cam disk is not displaced as shown by, the operating torque is changed from the torque on the first line 105 to the second line 1
Follow the transition that changes to torque on 06. In this case as well, holding at the intermediate detent position is achieved. In addition, at any position between the neutral position 34 and the most tilted position 35, if the operation is changed to return to the neutral position 34, the operation on the first line 105 is performed without the cam disk 32 being displaced. Follow the transition from torque to operating torque on the second line. Although the transition of the operating torque when the cam disk 32 is tilted from the neutral position 34 to the most tilted position 35 has been described with reference to FIG.
The same applies to the transition of the operating torque when the cam disk 32 is tilted from the neutral position 34 to the most tilted position 36.

According to the present embodiment, the cam disc 32
From the neutral position 34 to the first and second tilt directions B1, B
By tilting to any one of the two, a secondary pressure corresponding to the tilting angle from the neutral position 34 of the cam disk 32 is applied to one of the first and second output ports 42 and 43 corresponding to this tilting direction. An actuator (not shown) can be generated and remotely controlled. The cam disc 32 that displaces the first and second spools 40 and 41 in this way is tilted in the direction of returning to the neutral position 34 and from the neutral position 34 by the first and second return springs 48 and 49. A return spring force is provided that increases as the angle increases. Since the return spring force is applied to the cam disk 32 in this way, the operator receives a reaction force from the operation lever 37 due to the return spring and can obtain a suitable operation feeling.

In the hydraulically operated valve 30, the first rolling element 81 is in contact with the first contact area 80 of the cam disk 32 by the spring force of the first detent spring 82, and the cam disk 32 is also in contact. There are formed concave grooves 87, 88 into which the first rolling elements 81 fit when the cam disk is at the most tilted positions 35, 36. As a result, when the cam disk 32 is tilted to the most tilted positions 35 and 36, the first rolling elements 81 and 82 are fitted into the concave grooves 87 and 88 while being pressed by the detent spring force, and the cam disk 32 is It is possible to prevent the cam disk 32 from returning to the neutral position against the applied return spring force, so-called detent can be performed, and the cam 32 can be tilted to the maximum extent without applying an operating force to the cam disk 32. Can be held in position.

Further, in order to simplify the structure for pressing the first rolling element 81, the first detent spring 82 is used, and the detent spring force which is the pressing force for pressing the first rolling element 81 is used. Becomes larger as the first rolling element 81 moves away from the tilt axis L1. Further cam disc 3
The first contact area 80 of No. 2 has a position 64 where the first rolling element 81 abuts when the cam disk 32 is in the neutral position 34.
Therefore, when the cam disk 32 is in the most tilted positions 35, 36, the cam disk 32 is formed along the reference plane in which the distance from the tilt axis L1 increases toward the position where the contact member abuts. As a result, the cam disk 32 is placed in the neutral position 3
4, the first rolling element 81 tilt axis L1
, The detent spring force of the first detent spring 82 is reduced. Therefore, as the position approaches the neutral position 34, the frictional resistance force acting between the cam disk 32 and the first rolling element 81 becomes smaller.

Further, as shown in FIG. 5, the detent spring force indicated by the symbol F is given to the cam disk 32 from the first rolling element 81 and a part of the detent spring force indicated by the symbol F1, specifically, The component force in the direction perpendicular to the tangential plane of the cam disc 32 at the position 110 where the first rolling element 81 abuts acts in the direction of returning the cam disc 32 to the neutral position 34. That is, the component force F1 and this component force F
1. The contact position 110 and the tilt axis L1 in the direction perpendicular to the direction 1
The torque obtained by the product of the distance ΔD and the distance ΔD acts as the torque for returning the cam disk 32 to the neutral position. In this way, at a position other than the detent position, if the operator does not apply the operating torque, the cam disk 32 is moved to the neutral position even in the vicinity of the neutral position 34 by the combined force of the spring force of the first and second return springs and the detent spring force. Return.

As described above, in the vicinity of the neutral position, the frictional resistance between the first rolling element 81 and the cam disk 32 becomes small, and the operating torque and the neutral position 34 at the time of moving to the most tilted positions 35, 36. The torque difference ΔP from the operating torque when moving can be made smaller than in the conventional configuration, and the operability can be further improved.

As described above, the cam disk 32 can be held at the most tilted positions 35 and 36 to reduce the workload of the operator, facilitate the operation, and reduce the return spring force applied to the cam disk 32. As it approaches the neutral position 34, the frictional resistance force between the cam disc 32 and the first rolling element 81 is reduced, and the cam disc 32 is smoothly moved to the neutral position 34 by the restoring spring force and the restoring torque shown in FIG. And it can be reliably returned.

Further, the hydraulically operated valve 3 according to the downsizing of construction machinery
In response to the demand for downsizing of 0, shorten the operating lever 37,
Even if it is difficult to apply a large operating torque, the return spring force of the first and second return springs 48, 49 is reduced to facilitate the operation of the cam disk 32, thereby facilitating the operation and neutralizing the operation. The return operation to the position 34 can be favorably performed. Therefore, even if the hydraulic operation valve 30 is small and it is difficult to apply a large operation torque to the cam disc 32, the return spring force is reduced to facilitate the tilting operation of the cam disc and to move the cam disc 32 to the neutral position 34. The return operation can be improved. Further, such a hydraulically operated valve 30 can be realized by replacing only the cam disc with respect to the conventional hydraulically operated valve, and it is possible to realize the above-described excellent hydraulically operated valve without greatly improving the existing hydraulically operated valve. The hydraulically operated valve 30 can be easily obtained. Moreover, the cam disk 32 can be easily formed by cutting or grinding a conventional cam disk having a cylindrical outer peripheral surface as indicated by imaginary lines 113 and 114 in FIG. Further, it can be formed more easily by using the contact surface based on the flat surface as described above.

Further, by using the first detent spring 82 as the means for pressing the first rolling element 81, not only the structure can be simplified, but also the cap nut member 84 supports the first detent spring 82. With this configuration, the cap nut member 84 can be rotated and displaced in the axial direction with respect to the holding cylinder 83, and the spring force of the first detent spring can be changed.

Further, according to this embodiment, the second rolling element 91 is brought into contact with the second contact area 90 of the cam disk 32 by the second detent spring 92. This second
The contact area 90 of the neutral side area portion 74 near the position 75 with which the second rolling element 91 abuts when in the neutral position 34.
And the second rolling element 91 when in the most tilted positions 35, 36.
Have a stepped portion on the side close to the tilting axis L1 with respect to the neutral side area portion. Is formed. As a result, the second rolling element 91 comes into contact with the step flow region and the cam disk 32 is locked, so that the cam disk 32 can be held at such an intermediate detent position.

Further, in order to simplify the structure, the means for pressing the second rolling element 91 is realized by the second detent spring 92, and the detent spring force of the second rolling element 91 causes the second rolling element 91 to move from the tilt axis L1. It grows larger as it separates.
Further, the neutral side area portion and the most tilting side area portion have reference distances that increase from the tilting axis L1 toward the positions 68 and 69 at which the second rolling elements 91 abut when in the most tilting positions 35 and 36. Are formed along each. As a result, as it gets closer to the neutral position 34,
The second rolling element 91 is already close to the tilt axis L1, and the detent spring force of the second detent spring 92 is reduced. Therefore, as the position is closer to the neutral position 34, the frictional resistance force acting between the cam disk 32 and the second rolling element 91 becomes smaller. Further, according to the same principle as that described with reference to FIG. 5, the detent spring force applied from the second rolling element 91 to the cam disk 32 acts in the direction of returning it to the neutral position 34.

In addition to the mechanism for holding the cam disk 32 at the most tilted positions 35 and 36 as described above, a mechanism for holding the cam disk 32 at the intermediate position is provided, so that the cam disk 32 is held at the most tilted position as described above. 35,
36 and can be held in the neutral position 3 by the return spring force.
After making sure to be able to return to 4,
It is possible to be able to hold the cam disc in the intermediate position as well. Thus, the most tilted positions 35, 36
In addition to being able to be held in the intermediate position, the operation of the operator can be further facilitated.

In the present embodiment, the cam disc 32
Is held at the most tilted positions 35 and 36, the cam disk 32, the first rolling element 81, the first detent spring 82, the holding cylinder 83, the nut members 84 and 85, and the movable piece 86, The mechanism for holding the cam disc 32 at the intermediate position is the cam disc 32, the second rolling element 9
The first detent spring 92, the holding cylinder 93, the nut members 94 and 95, and the movable piece 96 are included.

FIG. 6 is a front view showing a cam disk 132 according to another embodiment of the present invention. Cam disc 132
Has a configuration similar to that of the above-described cam disk 32, and only different points will be described. In the cam disc 32, the region 63 of the first outer peripheral surface is formed as a flat surface, but the corresponding region 163 of the cam disc 132 is formed.
Is formed in a V-shape that is convex toward the tilt axis L1. The position 64 with which the first rolling element 81 abuts when the cam disk 132 is in the neutral position is located at the apex of the V-shape. In the cam disc 32, the area 7 of the second outer peripheral surface is
Although 4 is formed in a plane, the corresponding region 174 of the cam disk 132 is formed in a V shape that is convex toward the tilt axis L1. The position 75 with which the second rolling element 91 abuts when the cam disk 132 is in the neutral position is located at the apex of the V-shape. The other structure is the cam disk 32.
Is the same as.

Even if the cam disk 132 having such a structure is used, the same effect as when the cam disk 32 is used can be achieved. Further, in this way, each area 163,
By forming 174 in a V-shape, the neutral position 34
It can be configured so that a large operation torque is required at the time of the tilting operation from, and the operator can easily recognize the neutral position.

As still another form of the present embodiment, the regions corresponding to the regions 63, 163; 74, 174 have the first and second rolling elements 81, 91 at the most tilted positions 35, 36. The arcuate surface or the U-shaped surface may be convex in a direction away from the tilt axis L1 so that the distance from the tilt axis L1 increases toward the abutting position. Even with such a configuration, the same effect can be achieved.

As still another embodiment of the present invention, the cam disk 32 is provided so as to be tiltable around another tilt axis extending perpendicularly to the tilt axis L1 (left and right direction in FIG. 1), and the first and the first Third and fourth spool valves having the same structure as the second spool valve may be provided symmetrically with respect to an imaginary plane including the other tilt axis. The functions of the third and fourth spool valves are similar to those of the first and second spool valves, and an actuator different from the actuator controlled by the operation of the first and second spool valves is a hydraulically operated valve. It becomes possible to control remotely. At this time, also when tilting about the other tilt axis, the same detent mechanism for the cam disk 32 as when tilting about the tilt axis L1 may be provided to achieve the same effect.

As still another embodiment of the present invention, first and second detent springs 82 and 9 are used as pressing means for pressing the first and second rolling elements 81 and 91.
Instead of 2, an electromagnetic plunger having a plunger and a coil may be used. In this case as well, the electromagnetic force received by the plunger from the coil decreases as the amount of protrusion of the plunger with respect to the coil increases, and the same effect can be achieved.

As another embodiment of the present invention, it is also possible to adopt a structure in which a mechanism for achieving the intermediate detent is not provided. In this case, the relationship between the operating angle and the operating torque is as shown in FIG.
06b only changes linearly as shown by virtual lines 105c and 106c. Therefore, even with such a configuration, the same effect can be achieved except for the effect related to the mechanism of the intermediate detent.

Needless to say, the configuration can be changed within the scope of the present invention.

[0070]

According to the first aspect of the present invention, the restoring force increases as the tilting angle from the neutral position increases, so that the operator increases the operating force that increases as the tilting angle of the cam member increases. I have to give
A suitable operation feeling can be given. Further, in the vicinity of the neutral position, the frictional resistance force between the contact member and the cam member becomes small, and the operability is further improved. After obtaining such a feeling of operation, the contact member can be fitted and retained in the fitting recess at the most tilted position, so that the workload of the operator can be reduced and the operation can be performed. Can be easy. Moreover, in the vicinity of the neutral position of the cam member, the frictional resistance force between the contact members can be reduced, and the cam member can be reliably returned to the neutral position without the operator's operation. .

Even if the restoring force is reduced to facilitate the operation of the cam member, it is possible to favorably perform the returning operation of the cam member to the neutral position. Therefore, even if the hydraulically operated valve is small and it is difficult to apply a large operation torque to the cam member, the return force is reduced to facilitate the tilting operation of the cam member, and the return operation to the neutral position is good. Can be Further, such a hydraulically operated valve can be realized by replacing only the cam disc with the conventional hydraulically operated valve, and the excellent hydraulically operated valve as described above can be obtained without greatly improving the existing hydraulically operated valve. The operating valve can be easily obtained.

According to the second aspect of the present invention, the cam member can be held not only in the most tilted position but also in the intermediate position, and the operation by the operator can be further facilitated.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a hydraulic operation valve 30 according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing the vicinity of the cam disk 32 when the cam disk 32 is tilted.

FIG. 3 is a front view showing a cam disk 32.

FIG. 4 is a graph showing a relationship between an operation angle and an operation torque of the hydraulic operation valve 30.

FIG. 5 is a diagram for explaining a torque that acts on the cam disk 32 by the first detent spring 82.

FIG. 6 is a cam disc 132 according to another embodiment of the present invention.
FIG.

FIG. 7 is a cross-sectional view showing a conventional hydraulically operated valve 1.

FIG. 8 is a cross-sectional view showing the vicinity of the cam disk 3 when the cam disk 3 is tilted.

FIG. 9 is a graph showing a relationship between an operation angle and an operation torque in the hydraulic operation valve 1.

[Explanation of symbols]

30 hydraulically operated valve 31 housing 32 cam disc 33 axes 34 Neutral position 35,36 most tilted position 37 Control lever 40, 41 spool 42,43 output ports 44,45 Push rod 48, 49 Return spring 80, 90 contact area 81,91 rolling elements 82,83 Detent spring 84,94 Cap nut member 87,88 concave groove P pump port T tank port

Front page continuation (72) Inventor Akira Hanahara 6-1, Asahi-cho, Obu-shi, Aichi Prefecture Sumitomo Construction Machinery Co., Ltd., Nagoya Plant (56) References: Kaihei 7-22186 (JP, U) -198631 (JP, U) (58) Fields surveyed (Int.Cl. ⁷ , DB name) F16K 31/524 F16K 3/24 F16K 31/44

Claims (2)

(57) [Claims] 1. A cam member, which is tiltably supported between a neutral position and a most tilted position, and which is given a restoring force that increases in the direction of returning to the neutral position as the tilt angle from the neutral position increases. By tilting from the neutral position, the two spools are selectively displaced so that the output port corresponding to one of the spools communicates with the pump port, and the output port corresponding to the other spool and the tank. In a hydraulically operated valve that communicates with a port to generate a secondary pressure at an output port corresponding to one of the spools according to a tilt angle from a neutral position of the cam member, the hydraulic operation valve is close to the tilt axis of the cam member. And an abutting member that is displaceably displaceable and abuts in the abutting region of the outer peripheral surface of the cam member, and the abutting member separates from the tilt axis of the cam member. And a pressing means for pressing the contact member toward the tilt axis of the cam member by a pressing force that increases as the cam member increases, and the contact region of the outer peripheral surface of the cam member has the contact member when the cam member is in the neutral position. Is formed along a reference surface where the distance from the tilt axis of the cam member increases as the contact member abuts when the cam member is in the most tilted position. A hydraulically operated valve, characterized in that a fitting recess is formed in which the contact member fits when the cam member is at the most tilted position. 2. Another abutting member, which is provided so as to be displaceable toward and away from the tilt axis of the cam member and abuts in another abutting region of the cam member, and another abutting member. Includes another pressing means that presses the other contact member toward the tilt axis of the cam member by a pressing force that increases as the cam member moves away from the tilt axis of the cam member. The one contact area includes a neutral side area portion near the position where the other contact member abuts when the cam member is in the neutral position and a position near the position where the abutment member abuts when the cam member is in the most tilted position. A maximum tilting side area portion, and each area portion is a reference with which the distance from the tilt axis of the cam member increases as the cam member moves toward the position where another contact member abuts when the cam member is in the maximum tilting position. Along the surface The hydraulic operation according to claim 1, wherein the most tilting side region portion is formed to be continuous with the neutral side region portion with a step on the side closer to the tilting of the cam member. valve.