JPH0253642B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is mainly applicable to civil engineering work in which various working machines such as dozers and backhoes are mounted on a vehicle body on which crawlers driven by separate hydraulic motors are mounted on the left and right sides. This invention relates to improvements in a switching valve that is installed on a commercial vehicle and used to control the operation of left and right crawlers and work equipment, and a composite switching valve that combines these.

Conventionally, in a hydraulic circuit for a working machine of a civil engineering vehicle that is equipped with two hydraulic pumps and a plurality of actuators connecting them, the actuator of the working machine can be driven at twice the speed of driving the actuator of the working machine with a single hydraulic pump. In the case of driving a compound switching valve in which a large number of switching valves are incorporated in one valve body (valve frame) 14 as shown in FIG. 8, as shown in FIG. The operating levers were arranged in parallel, and the operating levers were mechanically interlocked with each other through connectors 20, and the hydraulic pressures discharged from the respective compound switching valves were combined through T-shaped joints 21, etc., to obtain double speed. However, this method requires a large number of pipes, requires a large space, has a complicated structure, and has low operational reliability.

In addition, in the circuit connecting the two hydraulic pumps and the two hydraulic motors, there is a circuit that switches between a single flow state where one hydraulic pump is connected to the two hydraulic motors and a combined state where both hydraulic pumps are connected. A flow/merging switching valve, a series/parallel switching valve that switches between connecting the two hydraulic motors in series and parallel to the hydraulic pump, and simultaneously switching the direction of oil flowing to the two hydraulic motors. A control means incorporating three switching valves, such as a two-system simultaneous directional switching valve, is also known, for example, from Japanese Utility Model Application Publication No. 122289/1989. However, as stated in the above-mentioned publication, this conventional means is capable of switching between single flow and combined flow, switching between series and parallel flow, and simultaneous direction switching of two systems.
The three switching operations are performed by operating separate switching valves, which makes the operation that much more troublesome, and requires three switching valves for each of the three switching operations. Since the configuration does not allow for continuous valve operation, the mechanism becomes complicated and expensive, and the piping becomes long, which reduces efficiency. It is not possible to perform a separate switching operation.

The purpose of the present invention is to simplify the switching operation and simplify the mechanism and piping by combining the several switching valves that perform several types of switching into one switching valve that enables multiple valves. The purpose of the present invention is to propose a new switching valve that can be manufactured at low cost and improves efficiency by significantly shortening the piping, and a composite switching valve that combines the same.

The invention will now be described with reference to illustrative embodiments.

In FIG. 1, reference numeral 1 denotes a valve body, and a main channel 3 through which a spool 2 can slide is formed so as to penetrate in the left-right direction.

10 and 11 on the valve body 1.
As shown in the figure, a pair of flow passages W ₁ and W 2 on the left and right, which communicate with the two pumps P ₁ and P ₂ , respectively, are located above the main flow passage ₃ , and are connected to the main flow passage 3 in a plan view. It is formed so as to penetrate in the front-rear direction, which is a direction perpendicular to the front-back direction.

Further, at a height position of the valve body 1 that overlaps with the main flow path 3, a pair of flow paths Y ₁ and Y ₂ on the left and right, which communicate with the two pumps P ₁ and P ₂ respectively, crosses the main flow path 3. The valve body 1 is formed so as to pass through the valve body 1 in the front and back directions, and the flow paths Y ₁ and Y ₂ communicate with the main flow path 3 at the portions where they intersect with the main flow path 3, respectively.

Furthermore, a tank line 7 communicating with the tank T is formed in a portion of the valve body 1 that is closer to the lower side than the main flow path 3 so as to penetrate the valve body 1 in the front and back directions.

Referring again to FIG. 1, the above-mentioned main flow path 3, which is provided so as to pass through the valve body 1 in the left-right direction, has ports 5A and 5B that communicate with flow paths 5 and 5, respectively, for actuating the actuator 4, and Branch flow paths 9P ₁ branched from the pair of flow paths W ₁ and W ₂ , respectively;
Each branch end port of 9P ₂ 10P ₁ , 11P ₁
and 10P ₂ , 11P ₂ and the openings 6P ₁ , 6 of the pair of channels Y ₁ , Y ₂ that cross the above-mentioned main channel 3
P ₂ , as well as the opening 7A of the tank line 7,
7B are opened and positioned symmetrically on the left and right. The positional relationship of these ports and openings is such that the openings 7A and 7B of the tank line 7 are located on both the left and right outermost sides, and the ports 5A and 5B of the flow paths 5 and 5 communicating with the actuator 4 are located on both inner sides thereof. are located, and one branch end port 10P 2 , 11P ₁ of the branch channels 9P ₁ , 9P ₂ branched from the channels W ₁ , W ₂ is located inside thereof, and one branch end port 10P 2 , 11P ₁ of the branch channel 9P ₁ , 9P ₂ is located inside thereof. The other branch end port 10P ₁ , 1
1P ₂ is located, and furthermore, a flow path Y ₁ ,
The respective openings 6P ₁ and 6P ₂ of Y ₂ are located close to each other.

The flow paths Y ₁ and Y ₂ that cross the main flow path 3 have an opening 6 with respect to the main flow path 3, as shown by the chain line in FIG.
P ₁ and 6P ₂ communicate as they are, but the flow path
W ₁ and W ₂ communicate with branch flow paths 9P ₁ and 9P ₂ via road check valves 8P ₁ and 8P ₂ , respectively.

One of the branch channels 9P ₁ and 9P ₂ , the branch channel 9P ₁ , has two branch end ports 1.
0P ₁ and 11P ₁ , which communicate with the main flow path 3 at portions close to the aforementioned 5A and 5B, respectively. On the other hand, the other branch channel 9P ₂ also communicates with the main channel 3 through two branch end ports 10P ₂ and 11P ₂ at locations close to the ports 5A and 5B, respectively. _The branch end port 10P ₁ and the branch end port 11P ₂ are in a bilaterally symmetrical positional relationship with each other in FIG _. be.

The spool 2 has five cylinder parts 2C ₁ ,
2C ₂ , 2C ₃ , 2C ₄ , 2C ₅ and four constrictions 2L ₁ ,
2L ₂ , 2L ₃ , and 2L ₄ are arranged in series alternately, and each part has the first part centered around the cylinder part 2C ₃ .
In the figure, it is symmetrical.

The length of the central cylinder part _2C3 is the main flow path 3.
The openings 6P ₁ of the two flow paths Y ₁ and Y ₂ that intersect with
6P ₂ , and in the neutral state (the state shown in FIG. 1), the cylinder portion 2C ₃ is within the spacing between the openings 6P ₁ and 6P ₂ of these channels Y ₁ and Y ₂ in the main flow channel 3. The openings 6P ₁ and 6P ₂ are set so as not to be blocked. In other words, the openings 6P ₁ and 6P ₂ are connected to the central cylinder portion 2 of the spool 2 when the spool 2 is in the neutral state.
It occupies a position facing the constricted portions 2L ₂ and 2L ₃ that are continuous on both sides of C ₃ and always allows passage of fluid from the pumps P ₁ and P ₂ .

The lengths of these constrictions 2L ₂ and 2L ₃ are such that in the neutral state, as shown in _FIG.
It faces the opening 6P ₁ of the channel Y ₂ or the opening 6P ₂ of the flow path Y 2.
As shown in Figure 4, only one of them is the flow path _Y1.
The opening _6P1 of the flow path _Y2 or the opening 6P2 of the flow path _Y2 is in a state where the other is located in the open part of the main flow path 3, and in the double operation state, either one faces the opening 6P1 of the flow path Y2 or the opening 6P2 of the flow path Y2. One constriction is located between the opening 6P ₁ of the channel Y ₁ and the opening 6P ₂ of the channel Y ₂ , and the other constriction faces the branch end port 10P ₁ or the branch end port 11P ₂ . is set to .

The lengths of the cylinder parts 2C ₂ and 2C ₄ that are continuous to the outside of these constricted parts 2L ₂ and 2L ₃ are the branch end ports 10P ₁ and 10P that are parallel to each other on the left side of the main flow path 3 in FIG. 1 in the neutral state. The branch end ports 11P ₁ and 11P ₂ which are parallel to each other on the right side _of the port 2 are blocked.

Furthermore, the lengths of the constricted portions 2L ₁ and 2L ₄ that are continuous on the outside of these cylinder portions 2C ₂ and 2C ₄ are the same as those of the two outside portions of the main flow path 3 in the neutral state as shown in FIG. Communicating ports 5A, 5B
It is set to face. In the single operating state, the length of the constricted portion _2L1 is as shown in FIG.
configured to enable communication with P ₂ , and
In the double operating state, as shown in FIG. 3, the configuration is such that communication between the port 5A, the branch end port _10P1 , and the branch end port _10P2 is enabled. In addition, the length of the constricted portion _2L4 is such that in the single operating state, the port 5B and the branch end port _11P1 can communicate with each other as shown in FIG. As shown in the figure, port 5B and branch end port 11
It is set to enable three-way communication between _P1 and the branch end port _11P2 .

Furthermore, the cylinder portions 2C ₁ and 2C ₅ that are continuous to the outside of the constricted portions 2L ₁ and 2L ₄ are as follows:
In the neutral state, the openings 7A and 7B of the tank line 7 are both blocked, as shown in FIG. 1, and in the single operating state, as shown in FIGS. Part 7
One of the openings 7A and 7B of the tank line 7 is blocked, and the other one is connected to the other of the openings 7A and 7B of the tank line 7, so that even in the double operation state, either one of the openings 7A and 7B is blocked, as shown in Figures 3 and 5. One of the openings 7A, 7B of the tank line 7 is blocked, and the other is configured to communicate with the other of the openings 7A, 7B of the tank line 7.

In this way, the valve body 1 and the spool 2 are configured to provide five states such as neutral, single operation, and double operation, but are not limited to these and can be configured to provide multiple other states. Sometimes it is done.

12 is the road check valve 8P ₁ , 8P ₂
13 is a spring that presses the valve 12. In addition, in FIG. 7, T ₁ and T ₂ are tank lines leading to the tank T.

Next, the main functions of the switching valve configured as described above will be explained.

In the neutral state, the spool ₂ is not subjected to any action, and as _shown in Fig.
Openings 6P ₁ and 6P ₂ of Y ₁ and Y ₂ are facing. Therefore, the fluid sent from the pumps P ₁ and P ₂ passes through the flow paths Y ₁ and Y ₂ that pass through the valve body 1 in the front and rear directions, and the spool 2 that is fitted therein crosses the main flow path 3. The water flows through the constrictions 2L ₂ and 2L ₃ and reaches the tank T as two separate streams. Therefore, pumps P ₁ and P ₂ can be operated without load. In this case, port 5
The actuator 4 connected to A and 5B is in a neutral state.

Forward rotation single flow/reverse rotation single flow As shown in Fig. 2, slide the spool 2 slightly to the right and block the opening 6P ₂ of one flow path Y ₂ with the central cylinder portion 2C ₃ . death,
The opening 6P ₁ of the other flow path Y ₁ is located within the range of the constriction 2L ₂ . At this time, the flow path
One branch end port 11P ₂ of the branch flow path 9P ₂ that can communicate with W ₂ is blocked by the cylinder part 2C ₄ , and the other branch end port 10P ₂ communicates with the port 5A through the constriction part 2L ₁ . do.
Therefore, the fluid sent from the pump P ₁ to the flow path Y ₁ flows from the opening 6P ₁ to the tank T through the constricted part 2L ₂ of the spool 2, as in the neutral state, but the fluid sent from the pump P ₂ flows to the tank T. The fluid sent to the path _Y2 is blocked by the cylinder portion _2C3 of the spool 2. Therefore, the fluid sent from pump _P2 is a separate flow path. From the flow path _W2, the valve 12 of the load check valve _8P2 is pushed up against the spring 13 to flow through the branched flow path _9P2 , from one branch end port _10P2 to the port 5A, and further to the actuator 4. It flows to the cylinder 4a of the cylinder 4a, and pushes up the piston 4b there from the head side. In synchronization with this, the fluid on the side opposite to the head of the piston 4b is pushed out to the port 5R, and is discharged into the tank through the opening of the tank line 7 which opens from the constriction _2L4 of the main flow path 3.

As shown in FIG. 4, the spool 2 is reversely slid slightly to the left, and the opening 6P ₁ of one channel Y ₁ is opened by the central cylinder portion 2C ₃ of the spool 2.
The opening _6P2 of the other channel _Y2 is located within the constriction _2L3 of the spool 2. At this time, one branch end port 10P ₁ of the branch flow path 9P ₁ that can communicate with the flow path W ₁ is
The other branch end port _11P1 is blocked by the cylinder portion _2C2 and communicates with the port 5B through the constriction portion _2L4 . The flow of fluid into the cylinder 4a of the actuator 4 is therefore opposite to that described above, reversing the movement of the piston 4b.

Forward rotation merging/reverse rotation merging As shown in Figure 3, the amount of sliding of the spool 2 to the right is increased, and the opening ₆ of one flow path Y1 is
_P1 is blocked by the cylinder portion _2C2 , and the opening _6P2 of the other channel _Y2 is also blocked by the central cylinder portion _2C3 . At this time, there are two branch channels 9 that can communicate with each of the channels W ₁ and W ₂ .
P ₁ and 9P ₂ each have one branch end port 10P ₁ and 10P ₂ communicating with the constriction portion 2L ₁ ,
The constricted portion _2L1 opens to the port 5A.
Therefore, the flow paths W ₁ , W ₂ from the two pumps P ₁ , P ₂
The fluid flowing to the road check valve 8P ₁ ,
8P ₂ to branch flow paths 9P ₁ and 9P ₂ , and from those branch end ports 10P ₁ and 10P ₂ , they merge at the constriction 2L ₁ of the spool 2, and are introduced into the cylinder 4a of the actuator 4 from the port 5A,
The piston 4b is pressed at twice the speed of the single flow. In synchronization with this, the fluid on the opposite side of the piston 4b is pushed out to the port 5B side and is discharged from the constricted portion _2L4 of the spool 2 to the tank line 7.

In Fig. 5, the spool 2 is reversely slid to the left by increasing the amount, and is operated in _a positional relationship symmetrical to that in Fig. _{3 .} , _W2 , the other branch end port _11P1 of the branch flow path _9P1 and the other branch end port _11P2 of the branch flow path _9P2 are connected to the spool 2.
The constriction 2L ₄ communicates with the constriction 2L ₄ .
communicates with the port 5B, so that they merge and are introduced into the cylinder 4a of the actuator 4 from the port 5B. As a result, actuator 4
operates in the opposite way to that shown in FIG.

When the above-described switching valve is used in a working machine, a plurality of switching valves are arranged in parallel in the valve frame 14 as a set, as shown in FIG _.
Fluid due to P ₂ always flows in two separate channels through each switching valve. In addition,
In FIG. 6, only a switching valve that provides only five positions is shown, but only two or three positions are shown.
Switching valves that provide arbitrary positions, such as one or four, may be selected and set in parallel in the valve frame 14 as a set.

FIG. 7 shows a practical application circuit for the use of the switching valve according to the invention. In the figure, inside the valve frame 14 are a plurality of actuating parts of the bucket hoe 15, such as a reversing actuator 4a of the bucket 16, an angle adjustment actuator 4 of the boom 17, etc.
switching valve a, which switches the operation of b, 4c, and 4d;
b, c, d... are set in parallel, and the driver's seat 18
It is now possible to operate. 19 is an operating lever.

Each of the switching valves a, b, c... is normally in a neutral state, and the oil sent from the two pumps P ₁ and P ₂ always flows in two streams. Now, by operating the operating lever 19, selector valve a
When set to the above-mentioned normal rotation merging position, the arms are rotatably connected to the tip of the arm which is bendably and rotatably connected to the tip side of the boom 17. The oil sent from the pumps _P1 and _P2 is combined with the actuator 4a, which is suspended between the actuator 4a and the bucket 16, and is fed so as to push out the piston. It rotates around the periphery, making it possible to perform excavation work with twice the force when set to the forward rotation single flow position. Conversely, when the bucket 16 is set to the reverse merging position, the bucket 16 rotates counterclockwise at twice the speed as in the case of reverse single flow in the same figure, and quickly releases the excavated soil that has been scooped out. become.

Next, during this operation, if the operating lever 19 of the switching valve b is moved to the same position as the operating lever 19 of the switching valve a, the flow path W ₁ ,
The oil from the pumps P ₁ and P ₂ flowing into the switching valves _a and b by W 2 flows into the actuator 4a that rotates the bucket 16 mentioned above and the boom 1.
7 and the actuator 4b that rotates the arm supported at the tip of the boom 17, the flow is fed in the following states according to the selected position: forward rotation single flow, forward rotation merging, reverse rotation single flow, and reverse rotation merging. You will be able to do it. Moreover, at this time, the switching valve c
If you also operate the operation lever 19 of the boom 1
The actuator 4c for up-and-down rotation of No. 7 also comes to operate at the same time. Therefore, a hydraulic circuit capable of switching multiple systems in the same direction is constructed.

Next, each switching valve a, b, c, d combined in parallel
By operating the operating levers 19 separately to select desired positions, the switching valves a, b, c, and d will be connected to the flow paths W ₁ and d, respectively.
Depending on the selected position, the oil from the two pumps P ₁ and P ₂ supplied by W ₂ is
It operates to switch each of the three actuators 4a, 4b, 4c, and 4d.

Therefore, the parallel switching valves a, b, and c constitute a circuit that can individually operate a plurality of systems in forward and reverse directions.

As explained above, although the switching valve according to the present invention configured as described above is a single switching valve, it can be operated to switch between forward rotation single flow, reverse rotation single flow, forward rotation merging, and reverse rotation merging. will be able to do it. In addition, as shown in Fig. 6, when used in parallel with multiple valves, the fluid from each pump can be switched between single flow and combined flow, and the actuators of multiple systems can be operated simultaneously and multiple systems can be operated simultaneously. It becomes possible to individually operate the actuators in forward and reverse directions.

Furthermore, since it can be integrated into a single valve frame to form a composite switching valve as shown in Fig. 6, it does not take up much space and requires no piping when used in a working machine with many actuators. Fewer composite switching valves can be obtained, and the connecting pipe for the operation lever and T-shaped pipe for piping connection to connect the single-flow type composite switching valve, which were used when conventionally combining composite switching valves, are omitted. become able to.

[Brief explanation of drawings]

1 to 5 show five views of a single switching valve according to the present invention.
FIG.
Fig. 1 is a vertical cross-sectional view showing the neutral state, Fig. 2 is a longitudinal cross-sectional view showing the normal rotation single flow state, Fig. 3 is a longitudinal cross-sectional view showing the normal rotation merging state, and Fig. 4 is a longitudinal cross-sectional view showing the normal rotation single flow state. FIG. 5 is a vertical cross-sectional view showing the reversed single flow state, FIG. 5 is a vertical cross-sectional view showing the reversed merging state, FIG. 6 is a circuit diagram of the switching valve group according to the present invention, and FIG. 7 is the same switching valve as above. Fig. 8 is a circuit diagram of a conventional switching valve group, and Fig. 9 is an applied circuit diagram when the same conventional switching valve group is used in a working machine.
Figure 10 is a vertical sectional side view taken along the - line in Figure 1;
The figure is a longitudinal side view taken along the line - - of Fig. 1, Fig. 12 is a longitudinal side view of a compound switching valve in which single switching valves are combined in parallel, and Fig. 13 is a longitudinal side view of the same compound switching valve at different cross-sectional positions. . Explanation of drawing symbols, T...tank, T ₁ , T ₂ ...
Tank line, P ₁ , P ₂ ... Pump, W ₁ , W ₂ ...
Flow path, a, b, c, d... switching valve, Y ₁ , Y ₂ ...
Flow path, 1... Valve body, 12... Valve, 13... Spring, 14... Valve frame, 15... Backhoe, 1
6...bucket, 17...boom, 18...driver's seat, 19...control lever, 2...spool, 2
C ₁ - 2C ₅ ... Cylinder part, 2L ₁ - 2L ₄ ... Neck part, 20 ... Connector, 21 ... T-shaped joint, 3 ... Main flow path, 4 ... Actuator, 4a ...
...Cylinder, 4b...Piston, 5...Flow path, 5
A, 5B...port, 6P ₁ , 6P ₂ ...opening,
7... Tank line, 7A, 7B... Opening, 8
P ₁ , 8P ₂ ... Road check valve, 9P ₁ , 9
P ₂ ... branch flow path, 10P ₁ , 10P ₂ ... branch end port, 11P ₁ , 11P ₂ ... branch end port.

Claims (1)

[Claims] 1. A main channel 3 in which the spool 2 can slide is provided in the left-right direction in the valve body 1, and the main channel 3 has ports for two channels 5, 5 which communicate with the actuator 4, respectively. 5A and 5B are opened as a pair on the left and right, and two flow paths Y _{1 and Y 2 are opened, which communicate with the two pumps P 1 and} P ₂ , respectively, cross and penetrate the main flow path 3, and lead to the tank _T. 6P ₁ and 6P ₂ are opened as a pair on the left and right, and two flow paths communicate with two pumps P ₁ and P ₂ separately from the two flow paths Y ₁ and Y ₂ .
Two branch channels 9 communicating with W ₁ and W ₂ respectively
Branch end ports 10P ₁ , 11P ₁ and branch end ports 10P ₂ , ₁ provided in each pair for P 1 , 9P ₂
Openings 7A, 7 of the tank line 7 which are opened laterally symmetrically with 1P ₂ and communicate with the tank T.
B are opened in pairs on the left and right, and a plurality of cylinder portions 2C ₁ are provided in the spool 2 to communicate and cut off each port and opening opened in the main flow path 3.
2C ₂ , 2C ₃ , 2C ₄ , 2C ₅ and constrictions 2L ₁ , 2L ₂ ,
2L ₃ and 2L ₄ are provided, and the two pumps P ₁ ,
It is characterized by being able to take out either one of the fluids sent from P ₂ as a forward rotation single flow or a reverse rotation single flow, and also to allow both fluids to be combined and selectively taken out as a forward rotation merge or a reverse rotation merge. A switching valve. 2. A main channel 3 in which the spool 2 can slide is provided in the left and right directions in the valve body 1, and in the main channel 3, ports 5A and 5B of two channels 5 and 5, which communicate with the actuator 4, respectively, are provided in the left and right directions. Openings _{6P 1} , 6P 2 of two channels Y _{1 , Y 2 are opened in pairs and communicate with the two pumps P 1 ,} P _{2 ,} respectively, and cross and penetrate the main channel ₃ to lead to the tank _T. are opened in pairs on the left and right, and two flow paths that communicate with two pumps P ₁ and P ₂ separately from the two flow paths Y ₁ and Y ₂ .
Two branch channels 9 communicating with W ₁ and W ₂ respectively
Branch end ports 10P ₁ , 11P ₁ and branch end ports 10P ₂ , ₁ provided in each pair for P 1 , 9P ₂
Openings 7A, 7 of the tank line 7 which are opened laterally symmetrically with 1P ₂ and communicate with the tank T.
B are opened in pairs on the left and right, and a plurality of cylinder portions 2C ₁ are provided in the spool 2 to communicate and cut off each port and opening opened in the main flow path 3.
2C ₂ , 2C ₃ , 2C ₄ , 2C ₅ and constrictions 2L ₁ , 2L ₂ ,
2L ₃ and 2L ₄ are installed in the same valve frame as a set, and a flow path leads to the pumps P ₁ and P ₂ and the tank T of each switching valve.
W ₁ , W ₂ , Y ₁ , Y ₂ and the tank line 7 penetrate the respective valve bodies 1 in the front and back to enable communication with each other, and the fluid from each pump can be switched and selected between single flow and combined flow. Also, a composite switching valve characterized in that it is configured so that the actuators of multiple systems can be operated simultaneously and the actuators of the multiple systems can be operated individually in forward and reverse directions.