JP2020083109A - Hydraulic circuit travel operation device and method and construction equipment using the same - Google Patents

Abstract

To provide a hydraulic circuit travel operation device and a method capable of allowing a driver to intuitively perform a driving operation with comfort, even when a driver drives in a front/rear reverse state, and construction equipment using the same.SOLUTION: There is provided a hydraulic circuit travel operation device for operating driving of a forward direction and a rearward direction of a travel device which is provided on each of right and left sides of a vehicle body, from an operation device 5 on a driver seat through a hydraulic circuit, the hydraulic circuit can be switched between a normal circuit arrangement in which, a left side travel device is driven in a cross direction by a first hydraulic signal S1 and a third hydraulic signal S3, and a right side travel device is driven in a cross direction by a second hydraulic signal S2 and a fourth hydraulic signal S4, and a reverse circuit arrangement in which, the left side travel device is driven in the cross direction by the second and fourth hydraulic signals S2, S4, and the right side travel device is driven in the cross direction by the first and third hydraulic signals S1, S3.SELECTED DRAWING: Figure 2

Description

The present invention relates to an apparatus and an operating method for operating traveling of a vehicle such as a construction machine via a hydraulic circuit, and a construction machine using the same.

For construction machines used at construction sites, etc., operating devices provided in the driver's seat operate traveling devices such as crawlers provided on the left and right of the vehicle body through hydraulic circuits to perform operations such as traveling and turning. There is.

FIG. 10 shows a crawler carrier 1 which is a kind of such construction machine. A crawler carrier (construction machine) 1 includes crawlers 3 as traveling devices on the left and right sides of a vehicle body 2, respectively, and an operator seat 4 on which a driver sits and an operation for operating the crawlers (traveling device) 3 in the front. A driver's seat 6 provided with the device 5 is provided. The operation device 5 is a joystick type device that inputs the tilting of the operation lever as a driving operation to the vehicle, and is attached to the side of the operator seat 4. In addition, in the crawler carrier 1 shown here, illustrations are omitted for the loading platform, the engine, and other components not directly related to the driving operation.

The crawler 3 is configured such that a left crawler (left side traveling device) 3A and a right side crawler (right side traveling device) 3B are driven in a forward direction or a reverse direction, respectively. The left crawler 3A and the right crawler 3B are operated in conjunction with each other or independently.

The operating device 5 is provided with a pilot valve 7 as shown in FIG. 11, and the pilot valve 7 has four valve main bodies (a front valve main body 7a, a rear valve main body 7b, and a left side valve main body 7a) at front, rear, left and right positions. A valve body 7c and a right valve body 7d) are arranged. These valve bodies 7a to 7d are configured to switch in accordance with tilting of the operating lever 8 to the front, rear, left and right, and the tilting of the operating lever 8 to the front, back, left and right is input to the hydraulic circuit as a hydraulic signal. It is like this.

FIG. 12 schematically shows a traveling operation of the crawler carrier 1 by tilting the operation lever 8. When the operating lever 8 is tilted forward, both the left crawler 3A and the right crawler 3B are driven in the forward direction, and the crawler carrier 1 goes straight forward (see FIG. 12(a)). When the operation lever 8 is tilted backward, both the left crawler 3A and the right crawler 3B are driven in the backward direction, and the crawler carrier 1 goes straight backward (see FIG. 12(b)). When the operation lever 8 is tilted to the left, the left crawler 3A is driven in the backward direction, while the right crawler 3B is driven in the forward direction, and the crawler carrier 1 makes a spin turn to turn counterclockwise on the spot (FIG. 12). (See (c)). When the operating lever 8 is tilted to the right, the left crawler 3A is driven in the forward direction, while the right crawler 3B is driven in the reverse direction, and the crawler carrier 1 makes a spin turn in which it rotates clockwise on the spot (Fig. 12 ( See d)).

When the operation lever 8 is tilted to the left front, the right crawler 3B is driven in the forward direction, and the crawler carrier 1 pivots counterclockwise and makes a forward pivot turn (see FIG. 12(e)). When the operating lever 8 is tilted to the right front, the left crawler 3A is driven in the forward direction, and the crawler carrier 1 makes a pivot turn to move forward while turning clockwise (see FIG. 12(f)). When the operating lever 8 is tilted to the right rear, the right crawler 3B is driven in the backward direction, and the crawler carrier 1 makes a pivot turn in which the crawler carrier 1 turns backward while rotating clockwise (see FIG. 12(g)). When the operation lever 8 is tilted to the left rear, the left crawler 3A is driven in the backward direction, and the crawler carrier 1 makes a pivotal turn in which the backward movement is performed while turning counterclockwise (see FIG. 12(h)).

The operation of the left and right crawlers 3 by the tilting of the operation lever 8 as shown in FIG. 12 is carried out, for example, via a hydraulic circuit as shown in FIG. The configuration of the hydraulic circuit will be described below.

In FIG. 13, E is an engine mounted on the crawler carrier 1 (see FIG. 10), and the left hydraulic pump 9 and the right hydraulic pump 10 are driven by the engine E. The left hydraulic pump 9 and the right hydraulic pump 10 drive a left hydraulic motor 11 and a right hydraulic motor 12, respectively, and the left hydraulic motor 11 and the right hydraulic motor 12 respectively drive the left traveling device (left crawler) 3A and the right traveling device. The right crawler 3B (see FIG. 10) is driven back and forth.

One of the inlet and outlet of the left hydraulic pump 9 is connected to one of the inlet and outlet of the left hydraulic motor 11 by a pipe line 13, and the other of the inlet and outlet of the left hydraulic pump 9 is connected to the other inlet and outlet of the left hydraulic motor 11 by a pipe line 14. The left and right hydraulic pumps 9 and 11 are connected to each other by the pipelines 13 and 14 to form a circulation path for circulating the pressure oil.

One of the entrance and exit of the right hydraulic pump 10 is connected to one of the entrance and exit of the right hydraulic motor 12 by a pipe line 15, and the other of the entrance and exit of the right hydraulic pump 10 is connected to the other entrance and exit of the right hydraulic motor 12 by a pipe line 16. The right and left hydraulic pumps 10 and 12 are connected by the pipe lines 15 and 16 to form a circulation path for circulating the pressure oil.

The left hydraulic pump 9 is provided with tilt angle adjusting units 17 and 18 for controlling forward drive and reverse drive of the left hydraulic motor 11, respectively. The tilt angle adjusting units 17 and 18 include a switching valve 19 The two ports are connected via conduits 20 and 21, respectively.

The right hydraulic pump 10 is provided with tilt angle adjusting units 22 and 23 for controlling forward drive and reverse drive of the right hydraulic motor 12, respectively, and the tilt angle adjusting units 22 and 23 include a switching valve 24. The two ports are connected via conduits 25 and 26, respectively.

In the switching valve 19 and the switching valve 24, P ports are connected to each other and R ports are connected to each other via conduits 27 and 28, respectively, and a middle portion of the conduit 27 connecting the P ports is for charging. It is connected to a conduit 30 from the hydraulic pump 29.

In the figure, 31 and 32 are combination valves connected to each other and connected to the pipelines 13 and 14, respectively, and 33 and 34 are combination valves connected to each other and connected to the pipelines 15 and 16, respectively. Is. Reference numerals 35 and 36 denote pipelines communicating with the combination valves 31, 32 or 33, 34, respectively, and both are connected to the charging hydraulic pump 29 via the pipeline 30.

On the operating device 5 side of the hydraulic circuit, the respective valve bodies 7a, 7b, 7c, 7d of the pilot valve 7 are connected in parallel to the operating hydraulic pump 37 via the pipe 38, and the T port is connected to the operating hydraulic pump 37. It is connected to the tank 39 via a pipe 40.

Four shuttle valves 41, 42, 43, 44 are provided in the pipelines downstream of the load side ports of the valve bodies 7a, 7b, 7c, 7d, and the four shuttle valves 41, 42, 43, From 44, a hydraulic signal is selectively sent to each switching port 19a, 19b and 24a, 24b of the switching valve 19, 24 via a pipe line.

The load side port of the valve body 7a on the front side is connected to one inlet port of the shuttle valve 41 and one inlet port of the shuttle valve 42 via a pipe 45 that branches downstream. The load side port of the valve body 7b on the rear side is connected to one inlet port of the shuttle valve 43 and one inlet port of the shuttle valve 44 via a pipe line 46 branched downstream.

The load side port of the left valve main body 7c is connected to the other inlet port of the shuttle valve 42 and the other inlet port of the shuttle valve 43 via a pipe line 47 branched downstream. The load side port of the right valve main body 7d is connected to the other inlet port of the shuttle valve 41 and the other inlet port of the shuttle valve 44 via a pipe line 48 that branches downstream.

One of the switching ports 19a of the switching valve 19 is connected to the outlet port of the shuttle valve 41 via a conduit 49. One of the switching ports 24a of the switching valve 24 is connected to the outlet port of the shuttle valve 42 via a conduit 50.

The other switching port 19b of the switching valve 19 is connected to the outlet port of the shuttle valve 43 via a pipe line 51. The other switching port 24b of the switching valve 24 is connected to the outlet port of the shuttle valve 44 via a pipe line 52.

A driving operation via the above hydraulic circuit will be described with reference to FIGS. 11 to 13.

(I) When the crawler carrier 1 goes straight ahead

When the operating lever 8 is tilted forward, the valve body 7a on the front side is switched (see FIG. 11), and the hydraulic pressure from the operating hydraulic pump 37 is transferred from the pipe line 45 downstream of the valve body 7a on the front side to the inlets of the shuttle valves 41 and 42. Sent to the port (see Figure 13). From the outlet port of the shuttle valve 41, hydraulic pressure is sent to the switching port 19a of the switching valve 19 via the pipe 49, and as a result, the switching valve 19 communicates with the pipes 27 and 20 and connects the pipes 28 and 21 with each other. Switch to communicate. From the outlet port of the shuttle valve 42, hydraulic pressure is sent to the switching port 24a of the switching valve 24 via the pipeline 50, and as a result, the switching valve 24 communicates with the pipelines 27 and 25 and connects the pipelines 28 and 26. Switch to communicate.

When the switching valve 19 is switched as described above, the hydraulic pressure of the charging hydraulic pump 29 is sent from the pipelines 30 and 27 to the pipeline 20 via the switching valve 19, and the tilt angle adjusting portion of the left hydraulic pump 9 is adjusted. Given to 17. The pressure oil discharged from the left hydraulic pump 9 circulates in the order of the pipeline 13, the left hydraulic motor 11, the pipeline 14, and the left hydraulic pump 9. As a result, the left hydraulic motor 11 drives the left crawler 3A in the forward direction.

When the switching valve 24 is switched as described above, the hydraulic pressure of the charging hydraulic pump 29 is sent from the pipelines 30, 27 to the pipeline 25 via the switching valve 24, and the tilt angle of the right hydraulic pump 10 is increased. It is given to the adjusting unit 22. The pressure oil discharged from the right hydraulic pump 10 circulates in the order of the pipe 15, the right hydraulic motor 12, the pipe 16, and the right hydraulic pump 10. As a result, the right hydraulic motor 12 drives the right crawler 3B in the forward direction.

When the left crawler 3A and the right crawler 3B are simultaneously driven in the forward direction, the crawler carrier 1 goes straight forward (see FIG. 12(a)).

(II) When the crawler carrier 1 goes straight backward

When the operation lever 8 is tilted backward, the rear valve body 7b is switched (see FIG. 11), and the hydraulic pressure from the operation hydraulic pump 37 is transferred from the pipeline 46 downstream of the rear valve body 7b to the shuttle valves 43 and 44. Is sent to the entrance port (see FIG. 13). From the outlet port of the shuttle valve 43, hydraulic pressure is sent to the switching port 19b of the switching valve 19 via the pipe line 51, and as a result, the switching valve 19 communicates with the pipe lines 27 and 21 and connects the pipe lines 28 and 20. Switch to communicate. From the outlet port of the shuttle valve 44, hydraulic pressure is sent to the switching port 24b of the switching valve 24 via the pipe line 52, so that the switching valve 24 communicates with the pipe lines 27 and 26 and connects the pipe lines 28 and 25. Switch to communicate.

When the switching valve 19 is switched as described above, the hydraulic pressure of the charging hydraulic pump 29 is sent from the pipelines 30 and 27 to the pipeline 21 via the switching valve 19 and the tilt angle adjusting portion of the left hydraulic pump 9 is adjusted. Given to 18. The pressure oil discharged from the left hydraulic pump 9 circulates in the order of the pipeline 14, the left hydraulic motor 11, the pipeline 13, and the left hydraulic pump 9. As a result, the left hydraulic motor 11 drives the left crawler 3A in the reverse direction.

When the switching valve 24 is switched as described above, the hydraulic pressure of the charging hydraulic pump 29 is sent from the pipelines 30, 27 to the pipeline 26 via the switching valve 24, and the tilt angle of the right hydraulic pump 10 is increased. It is given to the adjusting unit 23. The pressure oil discharged from the right hydraulic pump 10 circulates in the order of the pipe 16, the right hydraulic motor 12, the pipe 15, and the right hydraulic pump 10. As a result, the right hydraulic motor 12 drives the right crawler 3B in the reverse direction.

When the left crawler 3A and the right crawler 3B are simultaneously driven in the backward direction, the crawler carrier 1 goes straight backward (see FIG. 12(b)).

(III) When the crawler carrier 1 is spin-turned counterclockwise

When the operating lever 8 is tilted to the left, the left valve body 7c is switched (see FIG. 11), and the hydraulic pressure from the operating hydraulic pump 37 is transferred from the pipeline 47 downstream of the left valve body 7c to the inlets of the shuttle valves 42 and 43. Sent to the port (see Figure 13). From the outlet port of the shuttle valve 42, hydraulic pressure is sent to the switching port 24a of the switching valve 24 via the pipeline 50, so that the switching valve 24 communicates with the pipelines 27 and 25 and communicates with the pipelines 28 and 26. Switch to. The hydraulic pressure of the charging hydraulic pump 29 is sent to the pipeline 25 via the pipelines 30 and 27 and the switching valve 24 and given to the tilt angle adjusting section 22, and the pressure oil discharged from the right hydraulic pump 10 is the pipeline. 15, the right hydraulic motor 12, the conduit 16, and the right hydraulic pump 10 circulate in this order. As a result, the right hydraulic motor 12 drives the right crawler 3B in the forward direction.

From the outlet port of the shuttle valve 43, hydraulic pressure is sent to the switching port 19b of the switching valve 19 via the pipe 51 so that the switching valve 19 communicates with the pipes 27 and 21 and communicates with the pipes 28 and 20. Switch to. The hydraulic pressure of the charging hydraulic pump 29 is sent to the pipeline 21 via the pipelines 30 and 27 and the switching valve 19 and given to the tilt angle adjusting section 18, and the pressure oil discharged from the left hydraulic pump 9 is the pipeline. 14, the left hydraulic motor 11, the pipeline 13, and the left hydraulic pump 9 circulate in this order. As a result, the left hydraulic motor 11 drives the left crawler 3A in the reverse direction.

The left crawler 3A is driven in the backward direction, and at the same time, the right crawler 3B is also driven in the forward direction, whereby the crawler carrier 1 makes a spin turn to turn counterclockwise on the spot (see FIG. 12(c)).

(IV) When spin-turning the crawler carrier 1 clockwise

When the operating lever 8 is tilted to the right, the right valve body 7d is switched (see FIG. 11), and the hydraulic pressure from the operating hydraulic pump 37 is transferred from the pipeline 48 downstream of the right valve body 7d to the inlets of the shuttle valves 41 and 44. Sent to the port (see Figure 13). From the outlet port of the shuttle valve 41, hydraulic pressure is sent to the switching port 19a of the switching valve 19 via the pipe 49 so that the switching valve 19 communicates with the pipes 27 and 20 and communicates with the pipes 28 and 21. Switch to. The hydraulic pressure of the charging hydraulic pump 29 is sent to the pipeline 20 via the pipelines 30 and 27 and the switching valve 19 and given to the tilt angle adjusting section 17, and the pressure oil discharged from the left hydraulic pump 9 is the pipeline. 13, the left hydraulic motor 11, the pipeline 14, and the left hydraulic pump 9 circulate in this order. As a result, the left hydraulic motor 11 drives the left crawler 3A in the forward direction.

From the outlet port of the shuttle valve 44, hydraulic pressure is sent to the switching port 24b of the switching valve 24 via the pipe 52 so that the switching valve 24 communicates with the pipes 27 and 26 and communicates with the pipes 28 and 25. Switch to. The hydraulic pressure of the charge hydraulic pump 29 is sent to the pipeline 26 via the pipelines 30 and 27 and the switching valve 24 and given to the tilt angle adjusting section 23, and the pressure oil discharged from the right hydraulic pump 10 is the pipeline. 16, the right hydraulic motor 12, the conduit 15, and the right hydraulic pump 10 circulate in this order. As a result, the right hydraulic motor 12 drives the right crawler 3B in the reverse direction.

The left crawler 3A is driven in the forward direction, and at the same time, the right crawler 3B is driven in the backward direction, whereby the crawler carrier 1 makes a spin turn in which the crawler carrier 1 turns clockwise on the spot (see FIG. 12(d)).

To summarize the correspondence between the shuttle valves 41, 42, 43, 44 and the driving of the left and right crawlers 3, the hydraulic signal from the shuttle valve 41 is indirectly transmitted by switching the switching valve 19 from the switching port 19a side. To the tilt angle adjusting unit 17 to drive the left crawler 3A in the forward direction, and the hydraulic signal from the shuttle valve 42 indirectly adjusts the tilt angle by switching the switching valve 24 from the switching port 24a side. It is sent to the section 22 and drives the right crawler 3B in the forward direction. Further, the hydraulic signal from the shuttle valve 43 is indirectly sent to the tilt angle adjusting section 18 by switching the switching valve 19 from the switching port 19b side to drive the left crawler 3A in the backward direction and from the shuttle valve 44. The hydraulic signal is sent to the tilt angle adjusting unit 23 indirectly by switching the switching valve 24 from the switching port 24b side, and drives the right crawler 3B in the reverse direction.

That is, assuming that the hydraulic signals sent from the four shuttle valves 41, 42, 43, 44 are the first hydraulic signal S1, the second hydraulic signal S2, the third hydraulic signal S3, and the fourth hydraulic signal S4, respectively. , The first hydraulic signal S1 drives the left crawler 3A forward, the second hydraulic signal S2 drives the right crawler 3B forward, and the third hydraulic signal S3 drives the left crawler 3A backward. The four hydraulic signals S4 drive the reverse drive of the right crawler 3B.

Further, the valve bodies 7a, 7b, 7c, 7d provided in the pilot valve 7 are adapted to input the hydraulic pressure to two of the four shuttle valves 41, 42, 43, 44 by switching each. Therefore, each of the valve bodies 7a, 7b, 7c, 7d corresponds to two of the first to fourth hydraulic pressure signals S1, S2, S3, S4. That is, the first hydraulic signal S1 and the second hydraulic signal S2 are respectively input to the hydraulic circuit lines 49 and 50 by switching the front valve body 7a, and the hydraulic circuit pipes are switched by switching the rear valve body 7b. The third hydraulic signal S3 and the fourth hydraulic signal S4 are input to the passages 51 and 52, respectively, and the second hydraulic signal S2 and the third hydraulic signal S2 are input to the pipelines 50 and 51 of the hydraulic circuit by switching the left valve body 7c. The hydraulic signals S3 are input respectively, and the first hydraulic signal S1 and the fourth hydraulic signal S4 are input to the pipelines 49 and 52 of the hydraulic circuit by switching the right valve main body 7d.

Then, in the above-described forward-backward straight movement and spin turn operation, by switching any one of the valve bodies 7a, 7b, 7c, 7d, two corresponding hydraulic signals S1 to S4 are selectively selected. Is input to the hydraulic circuit and the left crawler 3A and the right crawler 3B are driven in conjunction with each other to perform a desired operation.

Next, the operation of pivoting the crawler carrier 1 will be described.

(V) When the crawler carrier 1 is pivoted to the left front

When the operating lever 8 is tilted to the left front, the valve body 7a on the front side and the valve body 7c on the left side are switched (see FIG. 11), and the hydraulic pressure from the operating hydraulic pump 37 is transferred from the downstream pipelines 45 and 47 to the shuttle valve 41. , 42, 43 to the inlet port (see FIG. 13). From the outlet port of the shuttle valve 42, hydraulic pressure is sent to the switching port 24a of the switching valve 24 via the pipe line 50. The switching valve 24 is switched so that the pipelines 27 and 25 communicate with each other and the pipelines 28 and 26 communicate with each other, and the hydraulic pressure of the charge hydraulic pump 29 is transferred from the pipeline 25 via the pipelines 30 and 27 and the switching valve 24. The pressure oil is supplied to the tilt angle adjusting unit 22, and the pressure oil is circulated by the right hydraulic pump 10, and the right hydraulic motor 12 drives the right crawler 3B in the forward direction.

At this time, hydraulic pressure is sent from the outlet port of the shuttle valve 41 to the switching port 19a of the switching valve 19 via the pipe 49, and hydraulic pressure is sent from the outlet port of the shuttle valve 43 to the switching valve 19a via the pipe 51. 19 to the switching port 19b. Since the hydraulic pressure acts on both the switching ports 19a and 19b in the switching valve 19, neither of the pipelines 20 and 21 is in a neutral state in which it communicates with the pipeline 27. Therefore, the pressure oil does not circulate on the left hydraulic pump 9 side, and the left hydraulic motor 11 is not driven.

That is, from the shuttle valves 41, 42 and 43, the first hydraulic signal S1 for driving the left crawler 3A forward, the second hydraulic signal S2 for driving the right crawler 3B forward, and the backward crawler 3A for driving the left crawler 3A, respectively. The third hydraulic signal S3 is input to the hydraulic circuit, but when the first hydraulic signal S1 and the third hydraulic signal S3 are input at the same time, the left hydraulic pump 9 is not driven, and therefore the left hydraulic motor 11 and the left hydraulic motor 11 are not driven. The crawler 3A is not driven. On the other hand, on the right hydraulic pump 10 side to which the second hydraulic signal S2 is input, the pressure oil circulates and the right hydraulic motor 12 operates to drive the right crawler 3B in the forward direction.

The left crawler 3A is not driven, and the right crawler 3B is driven in the forward direction, whereby the crawler carrier 1 makes a pivot turn to move forward while turning counterclockwise (see FIG. 12(e)). That is, when viewed from the driver, the vehicle moves forward while turning the front part of the vehicle to the left front.

(VI) When the crawler carrier 1 is pivoted to the front right

When the operating lever 8 is tilted to the right front, the front valve body 7a and the right valve body 7d are switched (see FIG. 11), and the hydraulic pressure from the operating hydraulic pump 37 is transferred from the downstream pipe lines 45 and 48 to the shuttle valve 41. , 42, 44 to the inlet port (see FIG. 13). From the outlet port of the shuttle valve 41, hydraulic pressure is sent to the switching port 19a of the switching valve 19 via the pipe 49. The switching valve 19 is switched so that the pipelines 27 and 20 communicate with each other and the pipelines 28 and 21 communicate with each other, and the hydraulic pressure of the charging hydraulic pump 29 is transferred from the pipeline 20 via the pipelines 30 and 27 and the switching valve 19. The left hydraulic pump 9 is supplied to the tilt angle adjusting unit 17 to circulate pressure oil, and the left hydraulic motor 11 drives the left crawler 3A in the forward direction.

At this time, hydraulic pressure is sent from the outlet port of the shuttle valve 42 to the switching port 24a of the switching valve 24 via the pipe 50, and hydraulic pressure is sent from the outlet port of the shuttle valve 44 to the switching valve 24 via the pipe 52. 24 of the switching ports 24b. Since the hydraulic pressure acts on both the switching ports 24a and 24b in the switching valve 24, neither of the conduits 25 and 26 is in a neutral state in which the conduit 25 is in communication with the conduit 27. Therefore, the pressure oil does not circulate on the right hydraulic pump 10 side, and the right hydraulic motor 12 is not driven.

That is, from the shuttle valves 41, 42, and 44, the first hydraulic signal S1 for driving the left crawler 3A forward, the second hydraulic signal S2 for driving the right crawler 3B forward, and the right crawler 3B for backward drive, respectively. The fourth hydraulic signal S4 is input to the hydraulic circuit, but when the second hydraulic signal S2 and the fourth hydraulic signal S4 are input at the same time, the right hydraulic pump 10 is not driven, and therefore the right hydraulic motor 12 and the right hydraulic motor 12 are not driven. The crawler 3B is not driven. On the other hand, pressure oil circulates on the left hydraulic pump 9 side to which the first hydraulic signal S1 is input, and the left hydraulic motor 11 operates to drive the left crawler 3A in the forward direction.

The right crawler 3B is not driven, and the left crawler 3A is driven in the forward direction, whereby the crawler carrier 1 makes a pivot turn to move forward while turning clockwise (see FIG. 12(f)). That is, as viewed from the driver, the vehicle moves forward while turning the front part of the vehicle to the right.

(VII) When pivoting the crawler carrier 1 to the left rear

When the operation lever 8 is tilted to the right rear, the valve body 7b on the rear side and the valve body 7d on the right side are switched (see FIG. 11), and the oil pressure from the operation hydraulic pump 37 is transferred from the downstream pipelines 46 and 48 to the shuttle valve. It is sent to the inlet ports 41, 43 and 44 (see FIG. 13). From the outlet port of the shuttle valve 44, the hydraulic pressure is sent to the switching port 24b of the switching valve 24 via the pipe line 52, and the hydraulic pressure of the charging hydraulic pump 29 is transferred to the switching line 24 via the pipe lines 30 and 27 and the switching valve 24. 26 is applied to the tilt angle adjusting unit 23, the pressure oil is circulated by the right hydraulic pump 10, and the right hydraulic motor 12 drives the right crawler 3B in the reverse direction.

At this time, the hydraulic pressure is sent from the outlet ports of the shuttle valves 41, 43 to the switching ports 19a, 19b, respectively, and the switching valve 19 sent to both switching ports 19a, 19b is in the neutral state. Therefore, the pressure oil does not circulate on the left hydraulic pump 9 side, and the left hydraulic motor 11 is not driven.

That is, from the shuttle valves 41, 43, 44, respectively, a first hydraulic signal S1 for driving the left crawler 3A forward, a third hydraulic signal S3 for driving the left crawler 3A in reverse, and a right hydraulic crawler 3B for driving backward. The fourth hydraulic signal S4 is input to the hydraulic circuit, but when the first hydraulic signal S1 and the third hydraulic signal S3 are input at the same time, the left hydraulic pump 9 is not driven, and therefore, the left hydraulic motor 11 and the left hydraulic motor 11 are not driven. The crawler 3A is not driven. On the other hand, on the right hydraulic pump 10 side to which the fourth hydraulic signal S4 is input, the pressure oil circulates and the right hydraulic motor 12 operates to drive the right crawler 3B in the reverse direction.

The left crawler 3A is not driven, and the right crawler 3B is driven in the backward direction, so that the crawler carrier 1 makes a pivot turn to move backward while turning clockwise (see FIG. 12(g)). That is, when viewed from the driver, the vehicle moves backward while turning the front part of the vehicle to the right and the tail part of the vehicle to the left.

(VIII) When pivoting the crawler carrier 1 to the right rear

When the operating lever 8 is tilted to the left rear, the valve body 7b on the rear side and the valve body 7c on the left side are switched (see FIG. 11), and the hydraulic pressure from the operating hydraulic pump 37 is transferred from the downstream pipelines 46 and 47 to the shuttle valve. It is sent to the inlet ports of 42, 43, 44 (see FIG. 13). From the outlet port of the shuttle valve 43, the hydraulic pressure is sent to the switching port 19b of the switching valve 19 via the pipe 51, and the hydraulic pressure of the charging hydraulic pump 29 is transferred to the switching port 19b via the pipes 30 and 27 and the switching valve 19. 21 is applied to the tilt angle adjusting unit 18, pressure oil is circulated by the left hydraulic pump 9, and the left hydraulic motor 11 drives the left crawler 3A in the reverse direction.

At this time, hydraulic pressure is sent from the outlet ports of the shuttle valves 42 and 44 to the switching ports 24a and 24b, respectively, and the switching valve 24 that has been sent hydraulic pressure to both switching ports 24a and 24b is in a neutral state. Therefore, the pressure oil does not circulate on the right hydraulic pump 10 side, and the right hydraulic motor 12 is not driven.

That is, from the shuttle valves 42, 43, and 44, the second hydraulic signal S2 for driving the right crawler 3B forward, the third hydraulic signal S3 for driving the left crawler 3A backward, and the right crawler 3B driving backward, respectively. The fourth hydraulic signal S4 is input to the hydraulic circuit, but when the second hydraulic signal S2 and the fourth hydraulic signal S4 are input at the same time, the right hydraulic pump 10 is not driven, and therefore the right hydraulic motor 12 and the right hydraulic motor 12 are not driven. The crawler 3B is not driven. On the other hand, on the left hydraulic pump 9 side to which the third hydraulic signal S3 is input, the pressure oil circulates and the left hydraulic motor 11 operates to drive the left crawler 3A in the reverse direction.

The right crawler 3B is not driven and the left crawler 3A is driven in the backward direction, so that the crawler carrier 1 makes a pivot turn to move backward while turning counterclockwise (see FIG. 12(h)). That is, as viewed from the driver, the vehicle moves backward while turning the front part of the vehicle to the left and the tail part of the vehicle to the right.

Thus, in the case of the pivot turn, by inputting the operation lever 8 in an oblique direction, two adjacent ones of the four valve bodies 7a, 7b, 7c, 7d are switched, and the hydraulic signals S1 to S4 are changed. Three of them are input to the hydraulic circuit. When the first hydraulic signal S1 for driving the left crawler 3A forward and the third hydraulic signal S3 for driving the left crawler 3A in reverse are input at the same time, the left crawler 3A is not driven and the right crawler 3A is not driven. If the second hydraulic signal S2 for driving the forward drive of 3B and the fourth hydraulic signal S4 for driving the reverse of the right crawler 3B are simultaneously input, the right crawler 3B is not driven. Therefore, when three of the hydraulic signals are input, as a result, only one of the hydraulic signals drives one of the crawlers 3 to the front or the rear to perform the pivot turn.

Note that, as a technical document describing a hydraulic circuit type traveling operation device using a pilot valve as described above and a construction machine using the same, for example, there is Patent Document 1 below.

JP, 2007-290543, A

By the way, in a construction site or the like, a situation in which a large vehicle such as a construction machine must pass through a narrow passage or a congested passage often occurs, and a delicate operation is often required for driving the vehicle. In particular, when it is desired to drive the vehicle backward, it may be desirable for the driver to turn over from the normal front direction and drive in the backward direction.

In the crawler carrier 1 of the conventional example described above, in such a case, the driver can sit on the guard 53 provided in front of the driver's seat 6 to perform the driving operation (see FIG. 10 ). This guard 53 is located in front of the operator seat 4, and the driver moves from the operator seat 4 to the guard 53 side as necessary, and operates the operation device 5 while facing the vehicle rear from this position. However, the crawler carrier 1 can be operated.

However, when only the driver sits backward and operates the operating device 5 while leaving the arrangement of the operating device 5 with respect to the driver's seat 6 and the corresponding relationship between the input direction of the operating lever 8 and the behavior of the left and right crawlers 3, the operating device 5 faces backward. There is a problem for the driver seated in the vehicle that the operation direction of the crawler 3 does not match the intuition depending on the input direction of the operation lever 8 (see FIGS. 11 and 12).

That is, when the driver operates the crawler carrier 1 backwards, there are cases in which the crawler carrier 1 may run to the front right or the front left (the rear left or the rear right for the vehicle) when viewed from the driver. For example, in order to pivot the crawler carrier 1 toward the front right (to the left rear for the vehicle) for the driver, the operation lever 8 must be tilted to the front left (to the rear right for the vehicle) for the driver. (See FIG. 12(g)). On the contrary, if the crawler carrier 1 is pivotally turned to the front left (to the right of the vehicle) for the driver, the operation lever 8 must be tilted to the front right (to the rear left of the vehicle) for the driver. (See FIG. 12(h)).

The same applies when the crawler carrier 1 is spun. In the case of driving in the front direction, for example, when the driver tilts the operation lever 8 to the right, the crawler carrier 1 turns clockwise, so that the driver turns the front part of the vehicle to the right, which is intuitive. It is easy to do (see FIG. 12(d)). However, in the case of driving backward, when the driver tilts the operation lever 8 to the right of the driver (left of the vehicle), the crawler carrier 1 turns counterclockwise, and the vehicle tail portion located in front of the driver. Turns to the left for the driver, and the operation input is in the opposite direction of intuition (see FIG. 12C).

That is, when the driver drives the crawler carrier 1 backwards, the driver's intuition regarding the input in the front-rear direction and the traveling direction of the crawler carrier 1 coincide with each other when performing the driving operation via the operation lever 8. Regarding the input of the direction, the intuition and the behavior of the crawler carrier 1 are reversed. This makes it very difficult to drive, and especially at a construction site, it may be necessary to frequently reverse the driving direction of the driver. Each time, the driver's intuitive input direction and the behavior of the crawler carrier 1 Correspondence may change, causing confusion, which may lead to erroneous operation.

In view of such a situation, the present invention uses a hydraulic circuit type traveling operation device and an operation method capable of intuitively and comfortably performing a driving operation even when a driver reverses and drives the vehicle, and uses the same. It aims to provide construction machinery.

The present invention relates to a hydraulic circuit type traveling operating device for operating, in a forward direction and a backward direction, a drive device provided on the left and right of a vehicle body from an operating device provided in a driver's seat through a hydraulic circuit. The left side traveling device of the traveling devices is driven in the forward direction by the first hydraulic pressure signal input to the hydraulic circuit, and is driven in the reverse direction by the third hydraulic pressure signal input to the hydraulic circuit. The right traveling device of the traveling devices is driven in the forward direction by the second hydraulic signal input to the hydraulic circuit, and is driven in the backward direction by the fourth hydraulic signal input to the hydraulic circuit. And the left side traveling device is driven in the forward direction by the second hydraulic signal while being driven in the backward direction by the fourth hydraulic signal, and the right side traveling device is A hydraulic circuit characterized by being configured to be switchable between a reverse circuit arrangement driven by a first hydraulic signal in the forward direction and driven by the third hydraulic signal in the reverse direction. The present invention relates to a traveling control device.

Thus, in this way, it is possible to switch the correspondence between the operation input to the operating device and the behavior of the traveling device between the normal position and the reverse position, which allows the operation to be performed during backward driving. The behavior of the traveling device with respect to the input can be oriented according to the driver's intuition.

In the hydraulic circuit type traveling operating device of the present invention, the operating device includes pilot valves in which four valve bodies are arranged at front, rear, left and right positions with respect to the vehicle, and tilts of the operating lever in the front, rear, left and right directions are performed by the four valves. It is configured to input the hydraulic pressure from the main body to the hydraulic circuit, and switching of the front valve main body among the four valve main bodies is performed by the first hydraulic pressure signal and the second hydraulic pressure signal of the hydraulic circuit. Of the four valve bodies, the switching of the rear valve body is input to the pipeline of the hydraulic circuit as the third hydraulic pressure signal and the fourth hydraulic pressure signal, and Among the main bodies, the switching of the left valve main body is input to the pipeline of the hydraulic circuit as the second hydraulic pressure signal and the third hydraulic pressure signal, and the switching of the right main valve body of the four valve main bodies is performed. The first hydraulic pressure signal and the fourth hydraulic pressure signal can be input to the pipeline of the hydraulic circuit, and by doing so, the circuit can be changed by connecting the pipelines to which the hydraulic pressure signal is sent. The arrangement can be switched, and a large-scale device or a complicated mechanism is not required for the switching.

In the hydraulic circuit type traveling operation device of the present invention, the operation device includes pilot valves in which four valve bodies are arranged at front right, left front, left rear, and right rear positions with respect to the vehicle, respectively. The tilt is configured to be input to the hydraulic circuit as hydraulic pressure from the four valve bodies, and the switching of the front right valve body of the four valve bodies is performed as the first hydraulic signal of the hydraulic circuit. Of the four valve bodies, the switching of the left front valve body is input to the pipeline of the hydraulic circuit as the second hydraulic signal, and the left rear valve of the four valve bodies is input. The switching of the main body is input to the pipeline of the hydraulic circuit as the third hydraulic signal, and the switching of the valve body on the right rear of the four valve bodies is the pipeline of the hydraulic circuit as the fourth hydraulic signal. Can be configured so that the circuit arrangement can be switched by switching the pipelines to which the hydraulic signals are sent, and a large-scale device or a complicated mechanism is not required for the switching. ..

In the hydraulic circuit type traveling operation device of the present invention, a pipe line to which the first hydraulic signal, the second hydraulic signal, the third hydraulic signal, and the fourth hydraulic signal are input to the hydraulic circuit. It is preferable that a selector valve for connecting the two to each other is provided, and the circuit arrangement at the normal position and the circuit arrangement at the reverse position are configured to be switchable by switching the selector valve. The mechanism for connecting the pipes to each other is simpler and the switching operation is simple.

In the hydraulic circuit type traveling operation device of the present invention, it is preferable that the driver's seat is provided with an operator seat that is reversible in the front-rear direction, and in this case, in the backward driving, the operator seat remains seated in the operator seat. The driving operation can be performed in a stable posture.

In the hydraulic circuit type traveling operation device according to the present invention, the operator seat is attached to the driver's seat so as to be turnable via a turntable, and the operator valve is switched in the front-rear direction by switching the selector valve. The operator seat can be turned back and forth by rotating the turntable, and the turning operation is simple. Moreover, since the operator seat is interlocked with the selector valve, the circuit arrangement can be switched by simply reversing the operator seat.

The present invention also relates to a construction machine to which the above-mentioned hydraulic circuit type traveling operation device is applied.

Further, the present invention is an operating method of a hydraulic circuit type traveling operating device, in which driving of a traveling device provided on the left and right of a vehicle body in a forward direction and a backward direction is operated via an hydraulic circuit from an operating device provided in a driver's seat. In the case where the driver is seated in the front direction in the driver's seat, the left traveling device of the traveling devices is driven in the forward direction by the first hydraulic signal input to the hydraulic circuit, The vehicle is driven in the reverse direction by a third hydraulic signal input to the hydraulic circuit, and the right-side traveling device of the traveling devices is driven in the forward direction by a second hydraulic signal input to the hydraulic circuit. When the vehicle is driven in the backward direction by the fourth hydraulic signal input to the hydraulic circuit and the driver is seated rearward in the driver's seat, the left-side traveling device operates in the forward direction by the second hydraulic signal. While being driven to the reverse direction by the fourth hydraulic signal, the right side traveling device is driven in the forward direction by the first hydraulic signal and driven in the reverse direction by the third hydraulic signal. The present invention relates to an operating method of a hydraulic circuit type traveling operation device characterized by the above.

According to the hydraulic circuit type traveling operation device and the operation method of the present invention, and the construction machine using the same, it is possible to intuitively and comfortably perform a driving operation even when the driver drives the vehicle by turning it back and forth. It can exert an excellent effect.

It is a top view showing an example of the form of the construction machine by operation of the present invention. It is a figure which shows an example of a structure of the hydraulic circuit in the hydraulic circuit type traveling operation device by implementation of this invention, and has shown the circuit arrangement|positioning of a normal position. It is a figure which shows an example of a structure of the hydraulic circuit in the hydraulic circuit type traveling operation device by implementation of this invention, and has shown the circuit arrangement|positioning of a reverse position. It is a perspective view showing an example of a selector valve used for operation of the present invention. It is sectional drawing which shows an example of the selector valve used for implementation of this invention, and is a VV arrow equivalent figure of FIG. (A) shows the state in the normal position, and (b) shows the state in the reverse position. In the construction machine according to the embodiment of the present invention, it is a conceptual diagram schematically showing a correspondence relationship between the input to the operating device and the behavior of the construction machine when the circuit arrangement is in the reverse position, and (a) to (h) are respective diagrams. The operation of the construction machine corresponding to the input direction is shown. It is a schematic perspective view which shows an example of the operating device of a construction machine. It is a figure which shows another example of a structure of the hydraulic circuit in the hydraulic circuit type traveling operation device by implementation of this invention, and has shown the circuit arrangement|positioning of a normal position. It is a figure which shows another example of a structure of the hydraulic circuit in the hydraulic circuit type traveling operation device by implementation of this invention, and has shown the circuit arrangement|positioning of a reverse position. It is a top view which shows an example of the form of the conventional construction machine. It is a schematic perspective view which shows an example of the operating device of a construction machine. It is a conceptual diagram which shows typically the correspondence of the input with respect to an operating device, and the behavior of a construction machine, (a)-(h) has shown the operation|movement of the construction machine corresponding to each input direction. It is a figure which shows an example of a structure of the hydraulic circuit in the conventional hydraulic circuit type travel operation device.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

1 to 5 show an example (first embodiment) of a hydraulic circuit type traveling operation device according to an embodiment of the present invention and a construction machine using the hydraulic circuit type traveling operation device. , The parts denoted by the same reference numerals as those in FIG. 13 represent the same things, and the basic configuration is the same as the conventional one shown in FIGS. 10, 11, and 13.

The first difference between the first embodiment and the conventional example is that, as shown in FIG. 1, the operator seat 54 provided in the driver's seat 6 of the crawler carrier 100, which is a construction machine, is installed on the floor of the driver's seat 6. It is attached to the floor of the driver's seat 6 so as to be horizontally rotatable via a turntable 55 provided in the. As a result, the operator seat 54 can be rotated in the horizontal direction about the turntable 55, and can be reversed in the front-rear direction between the front normal position indicated by the solid line and the backward reverse position indicated by the phantom line. There is.

The second difference is that, as shown in FIGS. 2 and 3, a selector valve 56 is provided in a pipeline downstream of the shuttle valves 41, 42, 43, 44 in the hydraulic circuit so that the connection between the pipelines can be switched. It can be mentioned that it is equipped with. The switching operation of the selector valve 56 is interlocked with the reversal of the operator seat 54 in the front-rear direction. When the operator seat 54 is in the normal position shown by the solid line in FIG. 1, the circuit arrangement in the normal position shown in FIG. When they are in the reverse positions shown by the phantom lines, they are switched to the reverse circuit arrangement shown in FIG. 3, respectively.

For example, as shown in FIGS. 4 and 5, the selector valve 56 has a plurality of conduits 58, 59, 60, 61 formed inside a cylindrical valve body 57, and the respective conduits 58, 59, 60 on its side surface. , 61 has openings 58a and 58b, 59a and 59b, 60a and 60b, and 61a and 61b, respectively.

As shown in FIGS. 5A and 5B, the eight openings 58a, 58b, 59a, 59b, 60a, 60b, 61a, 61b are divided into eight equal parts on the side surface of the cylindrical valve body 57. Are arranged in eight directions. 5A and 5B, the eight openings are arranged clockwise in the order of 58a, 61a, 61b, 59a, 58b, 60b, 60a, 59b, and the opening 58a is an opening on the opposite side of 180 degrees. 58b communicates with the pipeline 58, and the opening 59a adjacent to the opening 58b communicates with the opening 59b on the opposite side of 180 degrees with the pipeline 59. The opening 60a communicates with the adjacent opening 60b through the conduit 60, and the openings 60a and 60b are located between the openings 58b and 59b. The opening 61a communicates with the adjacent opening 61b through the pipe line 61, and the openings 61a and 61b are located between the openings 58a and 59a.

As shown in FIG. 4, a switching lever 62 is provided on one bottom surface of the valve body 57. By operating the switching lever 62 between a position shown by a solid line and a position shown by an imaginary line, a cylindrical shape is formed. By rotating the valve body 57 by 90 degrees in the circumferential direction, the valve body 57 can be switched between the normal position shown in FIG. 5A and the reverse position shown in FIG. 5B. With this switching operation, each of the conduits 58, 59, 60, 61 provided inside rotates 90 degrees, and the positions of the openings 58a, 58b, 59a, 59b, 60a, 60b, 61a, 61b are switched. The conduits connected to each opening can be reconnected.

The shape and configuration of the selector valve 56 are not limited to the example shown here. As long as it is possible to appropriately switch the communication relationship between the hydraulic circuit lines between the normal position and the reverse position, as will be described later, any connection may be used. For example, instead of the switching by rotation as shown in FIGS. 4 and 5, a switching system by electronic control can be adopted.

Further, the selector valve 56 does not necessarily have to interlock with the operator seat 54. The position of the selector valve 56 may be manually switched at the same time when the position of the operator seat 54 is switched.

The circuit configuration of the hydraulic circuit type traveling operation device of the first embodiment including the above selector valve 56 will be described with reference to FIGS. 2, 3 and 5.

In the above-mentioned conventional example shown in FIG. 13, the hydraulic signals S1, S2, S3, S4 from the shuttle valves 41, 42, 43, 44 are transmitted from the pipelines 49, 50, 51, 52 through the switching valve 19 or 24, respectively. The circuit configuration sent to the tilt angle adjusting units 17, 22, 18, 23 on the downstream side has been described as an example, but in the hydraulic circuit of the first embodiment, the pipelines 49, 50, 51, 52 of the conventional example described above are used. A selector valve 56 is provided in the middle of the pipe line corresponding to.

In the normal circuit arrangement, the selector valve 56 is arranged with respect to the pipeline of the hydraulic circuit as shown in FIGS. 2 and 5(a). The downstream of the conduit 63 (see FIG. 2) connected to the outlet port of the shuttle valve 41 is connected to one opening 58a of the conduit 58 of the selector valve 56 (see FIG. 5(a), above). The other opening 58b of the passage 58 is connected to the downstream pipe 64 (see FIG. 5(a), bottom). The pipe line 64 is connected to the tilt angle adjusting unit 17 of the left hydraulic pump 9 (see FIG. 2 ). The downstream of the pipe line 65 (see FIG. 2) connected to the outlet port of the shuttle valve 42 is connected to one opening 59a of the pipe line 59 of the selector valve 56 (see lower right in FIG. 5(a)), The other opening 59b of the conduit 59 is connected to the downstream conduit 66 (see the upper left in FIG. 5A). The pipe line 66 is connected to the tilt angle adjusting unit 22 of the right hydraulic pump 10 (see FIG. 2 ). The downstream side of the conduit 67 (see FIG. 2) connected to the outlet port of the shuttle valve 43 is connected to one opening 60a of the conduit 60 of the selector valve 56 (see left in FIG. 5(a)). The other opening 60b of the passage 60 is connected to the downstream pipe 68 (see the lower left in FIG. 5A). The pipe line 68 is connected to the tilt angle adjusting unit 18 of the left hydraulic pump 9 (see FIG. 2 ). The downstream side of the pipe 69 (see FIG. 2) connected to the outlet port of the shuttle valve 44 is connected to one opening 61a of the pipe 61 of the selector valve 56 (see the upper right of FIG. 5(a)). The other opening 61b of the passage 61 is connected to the downstream pipeline 70 (see right in FIG. 5A). The pipe line 70 is connected to the tilt angle adjusting unit 23 of the right hydraulic pump 10 (see FIG. 2 ).

In this state, the structure of the hydraulic circuit is basically the same as that of the conventional example shown in FIG. That is, as shown in FIG. 2, in the hydraulic circuit on the operating device 5 side, when the valve body 7a on the front side is switched, the hydraulic pressure from the operating hydraulic pump 37 is sent to the inlet ports of the shuttle valves 41 and 42, and the valve on the rear side is opened. When the main body 7b is switched, hydraulic pressure is sent to the inlet ports of the shuttle valves 43 and 44, when the left valve main body 7c is switched, hydraulic pressure is sent to the shuttle valve 42 and 43 inlet ports, and when the right main valve body 7d is switched, the hydraulic pressure is sent. Are sent to the inlet ports of shuttle valves 41 and 44. Further, the first hydraulic signal S1 from the shuttle valve 41 is sent downstream to the tilt angle adjusting section 17 to drive the left crawler 3A in the forward direction, and the second hydraulic signal S2 from the shuttle valve 42 is sent downstream. It is sent to the tilt angle adjusting unit 22 and drives the right crawler 3B in the forward direction. The third hydraulic signal S3 from the shuttle valve 43 is sent downstream to the tilt angle adjusting section 18 to drive the left crawler 3A in the backward direction, and the fourth hydraulic signal S4 from the shuttle valve 44 is sent downstream. It is sent to the tilt angle adjusting unit 23 to drive the right crawler 3B in the backward direction.

The circuit arrangement in the normal position shown in FIG. 2 is achieved by rotating the selector valve 56 by 90 degrees in the circumferential direction and switching from the normal position shown in FIG. 5(a) to the reverse position shown in FIG. 5(b). , The circuit arrangement is switched to the reverse position shown in FIG.

In the circuit arrangement shown in FIG. 3, pipe lines 63, 65, 67, 69 connected downstream of the four shuttle valves 41, 42, 43, 44 and tilt angle adjusting units 17, 18, 22, 23 are connected. In the selector valve 56 located between the conduits 64, 66, 68 and 70, the positions of the internal conduits 58, 59, 60 and 61 are switched. As a result, the pipe lines 63 to 70 themselves are not changed from the arrangements shown in FIGS. 2 and 5(a), and the pipe lines 63, 65, 67 and 69 and the pipe lines 64, 66, 68 and 70 are not changed. The contacts are being reconnected.

In this circuit arrangement, the downstream side of the conduit 63 (see FIG. 3) connected to the outlet port of the shuttle valve 41 is connected to one opening 61b of the conduit 61 of the selector valve 56 (see FIG. 5(b)). , Above), and the other opening 61a of the conduit 61 is connected to the downstream conduit 66 (see the upper left in FIG. 5B). The downstream of the pipe line 65 (see FIG. 3) connected to the outlet port of the shuttle valve 42 is connected to one opening 60b of the pipe line 60 of the selector valve 56 (see the lower right in FIG. 5(b)), The other opening 60a of the conduit 60 is connected to the downstream conduit 64 (see FIG. 5(b), bottom). The downstream side of the conduit 67 (see FIG. 3) connected to the outlet port of the shuttle valve 43 is connected to one opening 58a of the conduit 58 of the selector valve 56 (see left in FIG. 5(b)). The other opening 58b of the passage 58 is connected to the downstream pipe 70 (see right in FIG. 5B). The downstream side of the conduit 69 (see FIG. 3) connected to the outlet port of the shuttle valve 44 is connected to one opening 59a of the conduit 59 of the selector valve 56 (see upper right in FIG. 5(b)). The other opening 59b of the passage 59 is connected to the downstream pipe 68 (see the lower left of FIG. 5B).

Thus, as shown in FIG. 3, the pipeline 63 downstream of the shuttle valve 41 is connected to the pipeline 66 via the pipeline 61 of the selector valve 56, and the pipeline 65 downstream of the shuttle valve 42 is connected to the pipeline 60 of the selector valve 56. To the pipe 64, the pipe 67 downstream of the shuttle valve 43 to the pipe 70 via the pipe 58 of the selector valve 56, and the pipe 69 downstream of the shuttle valve 44 to the pipe 59 of the selector valve 56. The pipes 68 can be connected to each other via the.

Therefore, in the circuit configuration in the reverse position shown in FIG. 3, the first hydraulic signal S1 from the shuttle valve 41 is sent to the tilt angle adjusting section 22 via the pipe lines 63, 61, 66 to drive the right crawler 3B. Driving in the forward direction, the second hydraulic signal S2 from the shuttle valve 42 is sent to the tilt angle adjusting section 17 via the pipe lines 65, 60, 64 to drive the left crawler 3A in the forward direction. ing. Further, the third hydraulic signal S3 from the shuttle valve 43 is sent to the tilt angle adjusting section 23 via the pipes 67, 58, 70 to drive the right crawler 3B in the backward direction, and the third hydraulic signal S3 from the shuttle valve 44 is sent. The fourth hydraulic signal S4 is sent to the tilt angle adjusting section 18 via the conduits 69, 59, 68 to drive the left crawler 3A in the reverse direction.

In this way, the first hydraulic signal S1 that drives the left crawler 3A forward in the normal position circuit arrangement drives the right crawler 3B forward in the reverse position circuit arrangement, and moves forward. In the above, the second hydraulic signal S2 that has driven the right crawler 3B forward is driven to drive the left crawler 3A forward in the circuit arrangement at the reverse position. Further, the third hydraulic signal S3, which was driving the left crawler 3A in reverse in the normal position circuit arrangement, drives the right crawler 3B in reverse in the reverse position circuit arrangement, and is reverse driving in the normal position circuit arrangement. The fourth hydraulic signal S4, which was driving the reverse drive of the right crawler 3B, drives the reverse drive of the left crawler 3A in the reverse circuit arrangement. That is, in the normal circuit arrangement shown in FIG. 2 and the reverse circuit arrangement shown in FIG. 3, the left and right of the crawler 3 involved in each hydraulic signal are reversed.

The operation of the above first embodiment will be described.

First, the driving operation in the case of the normal circuit layout shown in FIG. 2 will be described. At this time, as described above, the configuration of the hydraulic circuit is basically the same as that of the conventional example shown in FIG. 13. Therefore, the correspondence relationship between the operation input of the operating device 5 and the behavior of the crawler carrier 100 is also the same as that of the conventional example. The same can be explained with reference to FIG. That is, when the operation lever 8 is tilted forward (see FIG. 11), the valve body 7a on the front side is switched and the first hydraulic signal S1 and the second hydraulic signal S2 are input to the hydraulic circuit (see FIG. 2). Both the left crawler 3A and the right crawler 3B are driven in the forward direction, and the crawler carrier 100 moves straight forward (see FIG. 12(a)). When the operating lever 8 is tilted backward (see FIG. 11), the rear valve body 7b is switched and the third hydraulic signal S3 and the fourth hydraulic signal S4 are input to the hydraulic circuit (see FIG. 2), and the left side Both the crawler 3A and the right crawler 3B are driven in the backward direction, and the crawler carrier 100 goes straight backward (see FIG. 12(b)).

When the operating lever 8 is tilted to the left (see FIG. 11), the left valve body 7c is switched and the second hydraulic signal S2 and the third hydraulic signal S3 are input to the hydraulic circuit (see FIG. 2), so that the left crawler is crawled. 3A is driven in the backward direction, while the right crawler 3B is driven in the forward direction, and the crawler carrier 100 makes a spin turn to turn counterclockwise on the spot (see FIG. 12C). When the operation lever 8 is tilted to the right (see FIG. 11), the right valve body 7d switches and the first hydraulic signal S1 and the fourth hydraulic signal S4 are input to the hydraulic circuit (see FIG. 2), and the left crawler 3A is driven in the forward direction, while the right crawler 3B is driven in the backward direction and the crawler carrier 100 makes a spin turn in which it rotates clockwise on the spot (see FIG. 12(d)).

Further, when the operation lever 8 is tilted to the left front (see FIG. 11), the front valve body 7a and the left valve body 7c are switched, and the shuttle valves 41, 42, 43 are switched to the first, second and third hydraulic pressures. The signals S1, S2, S3 are input (see FIG. 2). When the first hydraulic pressure signal S1 and the third hydraulic pressure signal S3 are simultaneously input, the hydraulic pressures are simultaneously input to the tilt angle adjusting units 17 and 18, so that the hydraulic oil does not circulate on the left hydraulic pump 9 side, and the left hydraulic pump 9 side does not circulate. The hydraulic motor 11 is not driven. On the right hydraulic pump 10 side, the second hydraulic signal S2 is input to the tilt angle adjusting unit 22, so the right hydraulic motor 12 drives the right crawler 3B in the forward direction, and the crawler carrier 100 turns counterclockwise. While making a forward pivot turn (see FIG. 12(e)).

When the operating lever 8 is tilted to the front right (see FIG. 11), the valve body 7a on the front side and the valve body 7d on the right side are switched, and the shuttle valves 41, 42, 44 transmit the first, second and fourth hydraulic pressure signals S1. , S2, S4 are input (see FIG. 2). When the second hydraulic pressure signal S2 and the fourth hydraulic pressure signal S4 are simultaneously input, the hydraulic pressure is simultaneously input to the tilt angle adjusting units 22 and 23, so that the hydraulic oil does not circulate on the right hydraulic pump 10 side and the right hydraulic pump 10 side does not circulate. The hydraulic motor 12 is not driven. On the left hydraulic pump 9 side, since the first hydraulic pressure signal S1 is input to the tilt angle adjusting unit 17, the left hydraulic motor 11 drives the left crawler 3A in the forward direction, and the crawler carrier 100 turns clockwise. A forward pivot turn is performed (see FIG. 12(f)).

When the operating lever 8 is tilted rearward to the right (see FIG. 11), the valve body 7b on the rear side and the valve body 7d on the right side are switched, and the first, third, and fourth hydraulic pressure signals are output from the shuttle valves 41, 43, 44. S1, S3 and S4 are input (see FIG. 2). When the first hydraulic pressure signal S1 and the third hydraulic pressure signal S3 are simultaneously input, the hydraulic pressures are simultaneously input to the tilt angle adjusting units 17 and 18, so that the hydraulic oil does not circulate on the left hydraulic pump 9 side, and the left hydraulic pump 9 side does not circulate. The hydraulic motor 11 is not driven. On the right hydraulic pump 10 side, the fourth hydraulic signal S4 is input to the tilt angle adjusting unit 23, so the right hydraulic motor 12 drives the right crawler 3B in the backward direction, and the crawler carrier 100 turns clockwise. Perform a backward pivot turn (see FIG. 12(g)).

When the operating lever 8 is tilted to the left rear (see FIG. 11), the rear valve body 7b and the left valve body 7c are switched, and the shuttle valves 42, 43, 44 send the second, third, and fourth hydraulic pressure signals. S2, S3 and S4 are input (see FIG. 2). When the second hydraulic pressure signal S2 and the fourth hydraulic pressure signal S4 are simultaneously input, the hydraulic pressure is simultaneously input to the tilt angle adjusting units 22 and 23, so that the hydraulic oil does not circulate on the right hydraulic pump 10 side and the right hydraulic pump 10 side does not circulate. The hydraulic motor 12 is not driven. On the left hydraulic pump 9 side, the third hydraulic signal S3 is input to the tilt angle adjusting unit 18, so the left hydraulic motor 11 drives the left crawler 3A in the backward direction, and the crawler carrier 100 turns counterclockwise. While making a reverse pivot turn (see FIG. 12(h)).

Next, the case of the circuit arrangement in the reverse position shown in FIG. 3 will be described.

It is assumed that, during operation of the crawler carrier 100, there is a case where it is desired to run the crawler carrier 100 backward. At that time, the driver moves the operator seat 54 from the normal position shown by the solid line in FIG. 1 to the reverse position shown by the phantom line, and shifts from the previous seated state facing front to the seating backward. To do. By doing so, a wider field of view behind the vehicle can be obtained as compared with the case of looking back behind the operator seat 54 in the normal position and driving operation can be performed in a stable posture while seated in the operator seat 54. it can.

At this time, since the operator seat 54 can be rotated by the turntable 55, the front and rear inversion operation is simple. Further, the operator seat 54 is interlocked with the selector valve 56 (see FIGS. 4 and 5), and as the operator seat 54 is moved to the reverse position, the selector valve 56 is also in the normal position (FIG. 5A). 3) to the reverse position (see FIG. 5B) automatically, and the hydraulic circuit also switches from the normal circuit layout shown in FIG. 2 to the reverse circuit layout shown in FIG.

Then, the driver seated in the operator seat 54 (see FIG. 1) that is turned upside down and is turned backward, operates the operation device 5 in a state where the operator sheet 54 is turned backward with respect to the vehicle, and drives the crawler carrier 100. Hereinafter, the driving operation in this state will be described for each input direction with reference to FIG.

(I) When the crawler carrier 100 goes straight backward (front of the driver)

When the operating lever 8 is tilted rearward (forward as viewed from the driver) (see FIG. 11), the rear valve body 7b is switched, and the hydraulic pressure from the operating hydraulic pump 37 is applied to the downstream valve body 7b. From path 46 to the inlet ports of shuttle valves 43 and 44 (see Figure 3). From the outlet port of the shuttle valve 43, a third hydraulic pressure signal S3 is sent to the tilt angle adjusting section 23 via the pipe lines 67, 58, 70 to drive the right crawler 3B in the backward direction, and the shuttle valve 44 outputs the signal. The fourth hydraulic signal S4 is sent to the tilt angle adjusting section 18 via the pipes 69, 59, 68 to drive the left crawler 3A in the reverse direction.

Both the left crawler 3A and the right crawler 3B are driven in the backward direction, and the crawler carrier 100 goes straight backward (forward as seen by the driver) (see FIG. 6A).

(II) When the crawler carrier 100 goes straight forward (backward when viewed from the driver)

When the operating lever 8 is tilted forward (backward when viewed from the driver) (see FIG. 11), the front valve body 7a is switched, and the hydraulic pressure from the operating hydraulic pump 37 is transferred to the pipe line 45 downstream of the front valve body 7a. To the inlet ports of shuttle valves 41 and 42 (see FIG. 3). From the outlet port of the shuttle valve 41, the first hydraulic signal S1 is sent to the tilt angle adjusting section 22 via the pipe lines 63, 61, 66 to drive the right crawler 3B in the forward direction, and the shuttle valve 42 outputs the first hydraulic signal S1. The second hydraulic signal S2 is sent to the tilt angle adjusting unit 17 via the conduits 65, 60, 64 to drive the left crawler 3A in the forward direction.

Both the left crawler 3A and the right crawler 3B are driven in the forward direction, and the crawler carrier 100 goes straight forward (backward when seen from the driver) (see FIG. 6B).

(III) When the crawler carrier 100 is spin-turned counterclockwise

When the operating lever 8 is tilted to the right (left for the driver) (see FIG. 11), the right valve main body 7d is switched, and the hydraulic pressure from the operating hydraulic pump 37 is transferred from the pipeline 48 downstream of the right valve main body 7d. Routed to the inlet ports of shuttle valves 41 and 44 (see FIG. 3). The first hydraulic signal S1 from the shuttle valve 41 is sent to the tilt angle adjusting unit 22 via the pipe lines 63, 61, 66 to drive the right crawler 3B in the forward direction, and the fourth hydraulic signal S1 from the shuttle valve 44 is sent. The hydraulic signal S4 is sent to the tilt angle adjusting unit 18 via the conduits 69, 59, 68 to drive the left crawler 3A in the reverse direction.

The left crawler 3A is driven in the backward direction, and at the same time, the right crawler 3B is driven in the forward direction, whereby the crawler carrier 100 spins counterclockwise (see FIG. 6C). Therefore, when the operating lever 8 is tilted to the left for the driver, the vehicle tail located ahead of the driver turns to the left for the driver.

(IV) When spin-turning the crawler carrier 100 clockwise

When the operating lever 8 is tilted to the left (to the driver's right) (see FIG. 11), the valve body 7c on the left side is switched, and the hydraulic pressure from the operating hydraulic pump 37 is supplied from the conduit 47 downstream of the valve body 7c on the left side. Routed to the inlet ports of shuttle valves 42 and 43 (see Figure 3). The second hydraulic signal S2 from the shuttle valve 42 is sent to the tilt angle adjusting section 17 via the pipes 65, 60, 64 to drive the left crawler 3A in the forward direction, and the third hydraulic signal S2 from the shuttle valve 43 is sent. The hydraulic signal S3 is sent to the tilt angle adjusting unit 23 via the conduits 67, 58, 70 to drive the right crawler 3B in the reverse direction.

The left crawler 3A is driven in the forward direction, and at the same time, the right crawler 3B is driven in the backward direction, whereby the crawler carrier 100 spins clockwise (see FIG. 6D). Therefore, when the operating lever 8 is tilted to the right for the driver, the vehicle tail located ahead of the driver turns to the right for the driver.

(V) When the crawler carrier 100 is pivot-turned to the right rear (front left for the driver)

When the operating lever 8 is tilted to the right rear (left front for the driver) (see FIG. 11), the valve body 7b on the rear side and the valve body 7d on the right side are switched, and the hydraulic pressure from the operating hydraulic pump 37 is changed to the downstream side. It is sent from the pipelines 46, 48 to the inlet ports of the shuttle valves 41, 43, 44 (see FIG. 3). The first hydraulic signal S1 from the shuttle valve 41 is sent to the tilt angle adjusting section 22 via the pipes 63, 61 and 66, while the third hydraulic signal S3 from the shuttle valve 43 is sent to the pipes 67 and 58. , 70 to the tilt angle adjusting section 23, and the tilt angle adjusting sections 22 and 23 simultaneously receive the hydraulic signals S1 and S3, respectively, the right hydraulic pump 10 does not circulate the pressure oil, and the right hydraulic motor 12 does not drive. Then, the fourth hydraulic signal S4 from the shuttle valve 44 is sent to the tilt angle adjusting section 18 via the pipes 69, 59, 68 to drive the left crawler 3A in the reverse direction.

The right crawler 3B is not driven, and the left crawler 3A is driven in the backward direction, whereby the crawler carrier 100 makes a pivot turn to move backward while turning counterclockwise (see FIG. 6(e)). Therefore, when the operating lever 8 is tilted to the front left for the driver, the crawler carrier 100 moves forward to the left for the driver while turning the vehicle tail located ahead of the driver for the driver to the left.

(VI) When the crawler carrier 100 is pivot-turned to the left rear (to the driver's right front)

When the operation lever 8 is tilted to the left rear (to the front right for the driver) (see FIG. 11), the valve body 7b on the rear side and the valve body 7c on the left side are switched, and the hydraulic pressure from the operation hydraulic pump 37 is changed to the downstream side. It is sent from the pipelines 46 and 47 to the inlet ports of the shuttle valves 42, 43 and 44 (see FIG. 3). The second hydraulic signal S2 from the shuttle valve 42 is sent to the tilt angle adjusting unit 17 via the pipes 65, 60 and 64, while the fourth hydraulic signal S4 from the shuttle valve 44 is sent to the pipes 69 and 59. , 68 to the tilt angle adjusting section 18 and the hydraulic signals S2 and S4 are simultaneously sent to the tilt angle adjusting sections 17 and 18, respectively. The left hydraulic pump 9 does not circulate the pressure oil and the left hydraulic motor 11 does not drive. Then, the third hydraulic signal S3 from the shuttle valve 43 is sent to the tilt angle adjusting section 23 via the pipes 67, 58, 70 to drive the right crawler 3B in the backward direction.

The left crawler 3A is not driven and the right crawler 3B is driven in the backward direction, so that the crawler carrier 100 makes a pivot turn to move backward while turning clockwise (see FIG. 6(f)). Therefore, when the operating lever 8 is tilted to the right front for the driver, the crawler carrier 100 moves forward to the right for the driver while turning the vehicle tail located ahead of the driver to the right for the driver.

(VII) When the crawler carrier 100 is pivoted to the front right (the rear left for the driver)

When the operation lever 8 is tilted to the front left (to the rear right for the driver) (see FIG. 11), the valve body 7a on the front side and the valve body 7c on the left side are switched, and the hydraulic pressure from the operation hydraulic pump 37 is applied to the downstream pipe. It is sent from the passages 45 and 47 to the inlet ports of the shuttle valves 41, 42 and 43 (see FIG. 3). The first hydraulic signal S1 from the shuttle valve 41 is sent to the tilt angle adjusting section 22 via the pipes 63, 61 and 66, while the third hydraulic signal S3 from the shuttle valve 43 is sent to the pipes 67 and 58. , 70 to the tilt angle adjusting section 23, and the tilt angle adjusting sections 22 and 23 simultaneously receive the hydraulic signals S1 and S3, respectively, the right hydraulic pump 10 does not circulate the pressure oil, and the right hydraulic motor 12 does not drive. Then, the second hydraulic signal S2 from the shuttle valve 42 is sent to the tilt angle adjusting section 17 via the conduits 65, 60, 64 to drive the left crawler 3A in the forward direction.

The right crawler 3B is not driven, but the left crawler 3A is driven in the forward direction, whereby the crawler carrier 100 makes a pivot turn to move forward while turning clockwise (see FIG. 6(g)). Therefore, when the driver leans the operation lever 8 rearward to the right, the crawler carrier 100 turns the vehicle tail located forward to the driver to the right and the vehicle front located rearward to the left while turning to the left for the driver. Go backward in the direction.

(VIII) When the crawler carrier 100 is pivot-turned to the front left (to the rear right of the driver)

When the operating lever 8 is tilted to the front right (to the left rear for the driver) (see FIG. 11), the front valve body 7a and the right valve body 7d are switched, and the hydraulic pressure from the operating hydraulic pump 37 is changed to the downstream pipe. It is sent from the passages 45 and 48 to the inlet ports of the shuttle valves 41, 42 and 44 (see FIG. 3). The second hydraulic signal S2 from the shuttle valve 42 is sent to the tilt angle adjusting unit 17 via the pipes 65, 60 and 64, while the fourth hydraulic signal S4 from the shuttle valve 44 is sent to the pipes 69 and 59. , 68 to the tilt angle adjusting section 18, and the hydraulic signals S2 and S4 are simultaneously sent to the tilt angle adjusting sections 17 and 18, respectively. The motor 11 is not driven. Then, the first hydraulic signal S1 from the shuttle valve 41 is sent to the tilt angle adjusting section 22 via the conduits 63, 61, 66 to drive the right crawler 3B in the forward direction.

The left crawler 3A is not driven, and the right crawler 3B is driven in the forward direction, whereby the crawler carrier 100 makes a pivot turn to move forward while turning counterclockwise (see FIG. 6(h)). Therefore, when the operation lever 8 is tilted to the left rear for the driver, the crawler carrier 100 turns the vehicle tail located in front of the driver to the left and the vehicle front located to the rear to the right while the driver moves to the right. Go backward in the direction.

As described above, in the first embodiment, when the driver drives the crawler carrier 100 backward, it is possible to switch the correspondence between the operation input to the operation device 5 and the behavior of the crawler carrier 100. Is becoming As a result, the behavior of the traveling device 3 or the crawler carrier 100 with respect to the input to the operation device 5 is oriented in the driver's intuition with respect to the left/right and left/right rearward movements of the vehicle, that is, the left/right and left/right frontward movements for the driver. Therefore, it is easy for the driver to perform a backward driving operation without causing any confusion during the driving operation.

The circuit arrangement is switched by connecting the pipelines in the hydraulic circuit and changing the paths of the hydraulic signals S1 to S4. When reversing the direction of operation, it is only necessary to reconnect the pipes in addition to reversing the operator seat 54. Therefore, the reversing operation is simple, and a large-scale device or a complicated device is required for switching the circuit arrangement. No special mechanism is required. Particularly in the case of the first embodiment, since the selector valves 56 provided in the hydraulic circuit are used to connect the pipes 63 to 70, the mechanism for connecting the pipes is simpler and the operation is simple. ..

Also regarding the joystick type operation device 5, when switching the circuit arrangement, for example, it is not necessary to rotate the operator seat 54 together, and the hydraulic signals S1 to Only the behavior of S4 or the crawler carrier 100 is reversed right and left. For example, it is necessary to provide the operating device 5 itself with a special mechanism or the like for switching the circuit arrangement, or to provide a plurality of operating devices 5, for example, for operating in the forward position and operating in the reverse position. Therefore, the rearward driving operation can be performed with the same operating device 5 installed in the driver's seat 6 in the same sense as when facing the front.

The operating device 5 is a small joystick type device and is provided beside the operator seat 54. Therefore, as compared with, for example, a construction machine of a type in which an operating lever is provided on the floor of the driver's seat, it is easier to reverse the operator seat 54 and get on and off the driver's seat 6.

Further, since the selector valve 56 and the operator seat 54 are interlocked with each other, it is not necessary for the driver to directly operate the selector valve 56, and the driver can simply switch the operator seat 54 to switch the circuit arrangement together. You can also do things. Therefore, it is possible to save the trouble of operating the selector valve 56, and at the same time, for example, in the case of backward operation, forgetting to switch the selector valve 56 from the normal position and performing the operation operation with the circuit arrangement in the normal position. In the front-facing operation, the operator does not forget to return the selector valve 56 from the reverse position and perform the driving operation with the circuit arrangement in the reverse position. Further, the operator seat 54 can be easily inverted by using the turntable 55.

As described above, in the first embodiment, the driving of the traveling devices (crawlers) 3 provided on the left and right of the vehicle body 2 in the forward and backward directions is performed from the operating device 5 provided in the driver's seat 6 via the hydraulic circuit. In the hydraulic circuit type traveling operation device, the left side traveling device (left side crawler) 3A of the traveling devices (crawlers) 3 is operated by a first hydraulic pressure signal S1 input to the hydraulic circuit. While being driven in the forward direction, it is driven in the reverse direction by the third hydraulic pressure signal S3 input to the hydraulic circuit, and the right traveling device (right crawler) 3B of the traveling device (crawler) 3 is connected to the hydraulic circuit. The circuit arrangement in the normal position is driven in the forward direction by the second hydraulic signal S2 input and is driven in the reverse direction by the fourth hydraulic signal S4 input to the hydraulic circuit, and the left traveling device (left side The crawler) 3A is driven in the forward direction by the second hydraulic signal S2, while it is driven in the reverse direction by the fourth hydraulic signal S4, and the right traveling device (right crawler) 3B is driven by the first hydraulic signal S1. While being driven in the forward direction, it is configured to be switchable between the reverse position circuit arrangement driven in the reverse direction by the third hydraulic signal S3, so that the operating device can be switched between the normal position and the reverse position. It is possible to switch the correspondence between the operation input to 5 and the behavior of the crawler 3, whereby the behavior of the crawler 3 with respect to the operation input can be oriented according to the driver's intuition during backward driving. ..

In addition, in the first embodiment, the operating device 5 includes the pilot valve 7 in which four valve bodies 7a, 7b, 7c, 7d are arranged at front, rear, left and right positions with respect to the vehicle, and the operating lever 8 is provided in the front, rear, left and right directions. The tilt is configured to be input to the hydraulic circuit as hydraulic pressure from the four valve bodies 7a, 7b, 7c, 7d, and the switching of the front valve body 7a among the four valve bodies is performed by the first hydraulic pressure. The signal S1 and the second hydraulic pressure signal S2 are input to the pipelines 63, 65 of the hydraulic circuit, and the switching of the rear valve main body 7b of the four valve main bodies is performed by the third hydraulic pressure signal S3 and the fourth hydraulic pressure signal S3. The hydraulic signal S4 is input to the pipelines 67 and 69 of the hydraulic circuit, and the switching of the left valve main body 7c of the four valve main bodies is performed as the second hydraulic signal S2 and the third hydraulic signal S3. Of the four valve bodies, and switching of the right valve body 7d among the four valve bodies is performed as the first hydraulic pressure signal S1 and the fourth hydraulic pressure signal S4 in the hydraulic circuit pipelines 63, 69. Since it is configured to be input, the circuit arrangement can be switched by switching the pipelines 63 to 70 to which the hydraulic signals S1 to S4 are sent, and a large-scale device or a complicated mechanism is not required for the switching.

Further, in the first embodiment, the conduits 63 through which the first hydraulic signal S1, the second hydraulic signal S2, the third hydraulic signal S3, and the fourth hydraulic signal S4 are input to the hydraulic circuit. Since the selector valve 56 for connecting 70 to each other is provided, and the circuit arrangement at the normal position and the circuit arrangement at the reverse position can be switched by switching the selector valve 56, the conduits 63 to 70 can be connected to each other. The mechanism for switching the connection is simpler and the switching operation is easier.

Further, in the first embodiment, the operator seat 54 is provided in the driver's seat 6 so as to be reversible in the front-rear direction, and therefore, when driving backwards, the operator can operate in a stable posture while seated on the operator seat 54. It can be carried out.

Further, in the first embodiment, the operator seat 54 is rotatably attached to the driver's seat 6 via the turntable 55, and the reversal of the operator seat 54 in the front-rear direction is interlocked with the switching of the selector valve 56. The operator seat 54 can be inverted back and forth by rotating the turntable 55, and the inversion operation is simple. Moreover, since the operator seat 54 is interlocked with the selector valve 56, the circuit arrangement can be switched by simply reversing the operator seat 54.

Therefore, according to the first embodiment described above, the driver can intuitively and comfortably perform the driving operation even when the driver reverses and drives the vehicle.

FIGS. 7 to 9 show another example (second embodiment) of the form of the hydraulic circuit type traveling operation device according to the present invention, and FIGS. 1 to 5 and FIGS. , The parts denoted by the same reference numerals as those in FIG. 13 represent the same things, and the basic structure is the same as the conventional one shown in FIGS. 10, 11, and 13 and the first embodiment shown in FIGS. Is.

The difference between the second embodiment and the first embodiment is that, as shown in FIG. 7, in the pilot valve 71 of the operating device 5, four valves for inputting the tilting of the operating lever 8 to the hydraulic circuit as hydraulic signals. This is that the main bodies 71a, 71b, 71c, 71d are arranged not at the front, rear, left and right but at the front right, front left, rear left and rear right, respectively.

Accordingly, the configuration of the hydraulic circuit on the operating device 5 side is also different from that of the first embodiment shown in FIG. 2, and as shown in FIGS. 8 and 9, the four valve bodies 71a, 71b, 71c are provided. , 71d are connected to the pipelines 63, 65, 67, 69 of the hydraulic circuit without passing through the shuttle valve. The switching of the front right valve body 71a is the first hydraulic pressure signal S1, the switching of the front left valve body 71b is the second hydraulic pressure signal S2, and the switching of the rear left valve body 71c is the third hydraulic pressure signal S3. The switching of the valve body 71d on the right rear side is input to the pipe lines 63, 65, 67, 69 as the fourth hydraulic pressure signal S4.

The configuration of the selector valve 56 on the downstream side of the pipe lines 63, 65, 67, 69 and the hydraulic circuit on the downstream side of the selector valve 56 is the same as that of the first embodiment shown in FIGS. 2 and 3. By switching the position of the selector valve 56 from the normal position to the reverse position, the configuration of the hydraulic circuit can be switched from the normal position circuit arrangement shown in FIG. 8 to the reverse position circuit arrangement shown in FIG. It is like this. That is, in the circuit arrangement in the normal position, as shown in FIG. 8, the pipe line 63 downstream of the right front valve body 71a is connected to the pipe line 64 via the pipe line 58 of the selector valve 56, and the pipe line downstream of the left front valve body 71b. The conduit 65 is connected to the conduit 66 via the conduit 59 of the selector valve 56, the conduit 67 downstream of the left rear valve body 71c is connected to the conduit 68 via the conduit 60 of the selector valve 56, and the right rear valve is connected. The pipeline 69 downstream of the main body 71d is connected to the pipeline 70 via the pipeline 61 of the selector valve 56, respectively, but in the circuit arrangement in the reverse position, as shown in FIG. The pipe line 63 is connected to the pipe line 66 via the pipe line 61 of the selector valve 56, the pipe line 65 downstream of the left front valve main body 71b is connected to the pipe line 64 via the pipe line 60 of the selector valve 56, and the left rear valve. The conduit 67 downstream of the main body 71c is connected to the conduit 70 via the conduit 58 of the selector valve 56, and the downstream conduit 69 of the right rear valve main body 71d is connected to the conduit 68 via the conduit 59 of the selector valve 56. Can be reconnected.

Then, in the normal position circuit arrangement shown in FIG. 8, the first hydraulic signal S1 from the valve body 71a on the front right side is sent to the tilt angle adjusting section 17 via the pipe lines 63, 58, 64, and is sent to the left crawler. 3A is driven in the forward direction, and the second hydraulic signal S2 from the front left valve body 71b is sent to the tilt angle adjusting section 22 via the pipe lines 65, 59, 66 to drive the right crawler 3B in the forward direction. Then, the third hydraulic signal S3 from the left rear valve body 71c is sent to the tilt angle adjusting section 18 via the pipe lines 67, 60, 68 to drive the left crawler 3A in the reverse direction, and the right rear The fourth hydraulic signal S4 from the valve body 71d is sent to the tilt angle adjusting section 23 via the pipes 69, 61 and 70 to drive the right crawler 3B in the reverse direction, while FIG. In the circuit arrangement in the reverse position shown in FIG. 1, the first hydraulic signal S1 from the valve body 71a on the right front side is sent to the tilt angle adjusting section 22 via the pipe lines 63, 61, 66 to move the right crawler 3B in the forward direction. The second hydraulic signal S2 from the front left valve body 71b is sent to the tilt angle adjusting unit 17 via the conduits 65, 60, 64 to drive the left crawler 3A in the forward direction, and the left rear The third hydraulic signal S3 from the valve main body 71c is sent to the tilt angle adjusting section 23 via the conduits 67, 58, 70 to drive the right crawler 3B in the backward direction, and from the right rear valve main body 71d. The fourth hydraulic pressure signal S4 is sent to the tilt angle adjusting portion 18 via the pipes 69, 59, 68 to drive the left crawler 3A in the backward direction, which is the same as the first embodiment. For each hydraulic signal, the right and left of the crawler 3 involved in the normal position and the reverse position are reversed.

The operation of the above second embodiment will be described.

In the normal position circuit arrangement as shown in FIG. 8, the correspondence relationship between the operation input to the operation device 5 and the behavior of the crawler 3 or the crawler carrier 100 is the normal position circuit in the above-mentioned conventional example or the first embodiment. The arrangement is similar to that of the arrangement, which can be described with reference to FIG.

When the operating lever 8 is tilted forward (see FIG. 7 ), the front right valve body 71a and the front left valve body 71b are switched, and the first hydraulic signal S1 and the second hydraulic signal S2 are input to the hydraulic circuit (FIG. 8), both the left crawler 3A and the right crawler 3B are driven in the forward direction, and the crawler carrier 100 moves straight forward (see FIG. 12(a)). When the operation lever 8 is tilted backward (see FIG. 7), the left rear valve body 71c and the right rear valve body 71d are switched, and the third hydraulic pressure signal S3 and the fourth hydraulic pressure signal S4 are input to the hydraulic circuit. (See FIG. 8), both the left crawler 3A and the right crawler 3B are driven in the backward direction, and the crawler carrier 100 goes straight backward (see FIG. 12B). When the operating lever 8 is tilted to the left (see FIG. 7), the valve body 71b on the front left and the valve body 71c on the rear left are switched, and the second hydraulic signal S2 and the third hydraulic signal S3 are input to the hydraulic circuit ( (See FIG. 8), while the left crawler 3A is driven in the reverse direction, the right crawler 3B is driven in the forward direction, and the crawler carrier 100 makes a spin turn to turn counterclockwise on the spot (see FIG. 12(c)). ). When the operation lever 8 is tilted to the right (see FIG. 7), the front right valve body 71a and the right rear valve body 71d are switched, and the first hydraulic signal S1 and the fourth hydraulic signal S4 are input to the hydraulic circuit ( (See FIG. 8), while the left crawler 3A is driven in the forward direction, the right crawler 3B is driven in the reverse direction and the crawler carrier 100 makes a spin turn in which it rotates clockwise on the spot (see FIG. 12(d)). ..

When the operation lever 8 is tilted to the left front (see FIG. 7), the front left valve body 71b is switched to input the second hydraulic signal S2 for driving the right crawler 3B forward (see FIG. 8), and the crawler carrier 100 is moved. A pivot turn is made to move forward while turning counterclockwise (see FIG. 12(e)). When the operating lever 8 is tilted to the right front (see FIG. 7), the front right valve body 71a is switched and the first hydraulic signal S1 for driving the left crawler 3A forward is input (see FIG. 8), and the crawler carrier 100 is moved. A pivot turn is made to move forward while turning clockwise (see FIG. 12(f)). When the operation lever 8 is tilted rearward to the right (see FIG. 7), the right rear valve body 71d is switched to input the fourth hydraulic signal S4 for driving the right crawler 3B in the reverse direction (see FIG. 8), The carrier 100 makes a backward pivoting turn while turning clockwise (see FIG. 12(g)). When the operating lever 8 is tilted to the left rear (see FIG. 7), the left rear valve body 71c is switched and the third hydraulic signal S3 for driving the left crawler 3A in the backward direction is input (see FIG. 8), and the crawler carrier 100 is received. Makes a reverse pivot turn while turning counterclockwise (see FIG. 12(h)).

As described above, with the configuration of the pilot valve 71 and the hydraulic circuit as in the second embodiment, the operation of the crawler carrier 100 can be performed with the same feeling as in the first embodiment in the circuit arrangement at the normal position. .. When an operation input is performed in an oblique direction, three hydraulic signals among the first to fourth hydraulic signals S1 to S4 are input to the circuit in the first embodiment, and one hydraulic signal is input in the second embodiment. Although there are differences such as input, there is no significant difference in terms of driving operation via the operation lever 8.

A driving operation in the circuit arrangement in the case of the reverse position as shown in FIG. 9 will be described. In this case, the correspondence relationship between the operation input to the operation device 5 and the behavior of the crawler 3 or the crawler carrier 100 is the same as the case of the reverse circuit arrangement in the first embodiment described above, and will be described with reference to FIG. it can.

When the operating lever 8 is tilted rearward (forward for the driver) (see FIG. 7), the left rear valve body 71c and the right rear valve body 71d are switched, and the third hydraulic pressure signal S3 and the fourth hydraulic pressure signal S4 are switched. Is input to the hydraulic circuit (see FIG. 9). The third hydraulic signal S3 drives the right crawler 3B in the backward direction, and the fourth hydraulic signal S4 drives the left crawler 3A in the backward direction, so that the crawler carrier 100 goes straight backward (forward for the driver) ( FIG. 6A).

When the operating lever 8 is tilted forward (backward for the driver) (see FIG. 7), the front right valve body 71a and the front left valve body 71b are switched, and the first hydraulic pressure signal S1 and the second hydraulic pressure signal S2 are changed to hydraulic pressure. It is input to the circuit (see FIG. 9). The first hydraulic signal S1 drives the right crawler 3B in the forward direction, and the second hydraulic signal S2 drives the left crawler 3A in the forward direction, so that the crawler carrier 100 goes straight forward (backward for the driver) ( See FIG. 6B).

When the operating lever 8 is tilted to the right (to the left of the driver) (see FIG. 7), the valve body 71a on the front right side and the valve body 71d on the rear right side are switched, and the first hydraulic pressure signal S1 and the fourth hydraulic pressure signal S4 are transmitted. Input to the hydraulic circuit (see FIG. 9). The first hydraulic signal S1 drives the right crawler 3B in the forward direction, and the fourth hydraulic signal S4 drives the left crawler 3A in the backward direction, so that the crawler carrier 100 spins counterclockwise (FIG. 6( See c)). That is, for the driver, the vehicle tail located in the front turns to the left.

When the operation lever 8 is tilted to the left (to the right for the driver) (see FIG. 7), the valve body 71b on the front left side and the valve body 71c on the rear left side are switched, and the second hydraulic pressure signal S2 and the third hydraulic pressure signal S3 are transmitted. Input to the hydraulic circuit (see FIG. 9). The second hydraulic signal S2 drives the left crawler 3A in the forward direction, and the third hydraulic signal S3 drives the right crawler 3B in the backward direction, so that the crawler carrier 100 spins clockwise (FIG. 6(d). )reference). That is, for the driver, the vehicle tail located in the front turns to the right.

When the operating lever 8 is tilted to the right rear (left front for the driver) (see FIG. 7), the valve body 71d on the right rear is switched and the fourth hydraulic signal S4 is input to the hydraulic circuit (see FIG. 9). .. The fourth hydraulic signal S4 drives the left crawler 3A in the backward direction, and the crawler carrier 100 makes a pivotal turn backward while turning counterclockwise (see FIG. 6(e)). That is, for the driver, the vehicle tail located in front is turned leftward while turning to the left.

When the operating lever 8 is tilted to the left rear (to the driver's right front) (see FIG. 7), the left rear valve body 71c is switched and the third hydraulic signal S3 is input to the hydraulic circuit (see FIG. 9). .. The third hydraulic signal S3 drives the right crawler 3B in the backward direction, and the crawler carrier 100 makes a pivot turn to move backward while turning clockwise (see FIG. 6(f)). That is, for the driver, the vehicle tail located in the front is turned to the right while turning to the right.

When the operation lever 8 is tilted to the front left (to the right rear for the driver) (see FIG. 7), the valve body 71b on the front left is switched and the second hydraulic signal S2 is input to the hydraulic circuit (see FIG. 9). The second hydraulic signal S2 drives the left crawler 3A in the forward direction, and the crawler carrier 100 makes a pivot turn to move forward while turning clockwise (see FIG. 6(g)). That is, for the driver, the vehicle moves backward to the left while turning the front portion of the vehicle located behind to the left.

When the operating lever 8 is tilted to the right front (left rear for the driver) (see FIG. 7), the valve body 71a on the right front is switched and the first hydraulic signal S1 is input to the hydraulic circuit (see FIG. 9). The first hydraulic signal S1 drives the right crawler 3B in the forward direction, and the crawler carrier 100 makes a pivot turn to move forward while turning counterclockwise (see FIG. 6(h)). That is, for the driver, the vehicle moves backward while turning the front part of the vehicle located at the rear to the right.

As described above, even in the reverse circuit arrangement, the driving operation of the crawler carrier 100 can be performed with the same feeling as in the first embodiment.

The pilot valve for inputting the operation is not limited to the configuration like the pilot valve 7 shown in the first and second embodiments, and the appropriate operation as described above can be input to each crawler. Anything will do as long as it is. For example, a signal according to the tilting direction of the operation lever may be input by electronic control.

As described above, in the second embodiment, the driving device (crawler) 3 provided on the left and right of the vehicle body 2 is driven in the forward and backward directions from the operating device 5 provided in the driver's seat 6 via the hydraulic circuit. In the hydraulic circuit type traveling operation device, the left side traveling device (left side crawler) 3A of the traveling devices (crawlers) 3 is operated by a first hydraulic pressure signal S1 input to the hydraulic circuit. While being driven in the forward direction, it is driven in the reverse direction by the third hydraulic pressure signal S3 input to the hydraulic circuit, and the right traveling device (right crawler) 3B of the traveling device (crawler) 3 is connected to the hydraulic circuit. The circuit arrangement in the normal position is driven in the forward direction by the second hydraulic signal S2 input and is driven in the reverse direction by the fourth hydraulic signal S4 input to the hydraulic circuit, and the left traveling device (left side The crawler) 3A is driven in the forward direction by the second hydraulic signal S2, while it is driven in the reverse direction by the fourth hydraulic signal S4, and the right traveling device (right crawler) 3B is driven by the first hydraulic signal S1. While being driven in the forward direction, it is configured to be switchable between the reverse position circuit arrangement driven in the reverse direction by the third hydraulic signal S3, so that the operating device can be switched between the normal position and the reverse position. It is possible to switch the correspondence between the operation input to 5 and the behavior of the crawler 3, whereby the behavior of the crawler 3 with respect to the operation input can be oriented according to the driver's intuition during backward driving. ..

Further, in the second embodiment, the operating device 5 is provided with pilot valves 71 in which four valve bodies 71a, 71b, 71c, 71d are arranged at respective positions of front right, front left, rear left, rear right with respect to the vehicle. The tilting of the lever 8 in the front-rear and left-right directions is configured to be input to the hydraulic circuit as hydraulic pressure from the four valve bodies 71a, 71b, 71c, 71d, and the front right valve body 71a of the four valve bodies is Is input to the conduit 63 of the hydraulic circuit as a first hydraulic signal S1, and the switching of the left front valve main body 71b of the four valve main bodies is switched to the second hydraulic signal S2 as a pipe of the hydraulic circuit. Of the four valve bodies, the switching of the left rear valve body 71c of the four valve bodies is input as a third hydraulic pressure signal S3 to the pipeline 67 of the hydraulic circuit, and the right valve of the four valve bodies is input. Since the subsequent switching of the valve main body 71d is configured to be input to the pipeline 69 of the hydraulic circuit as the fourth hydraulic pressure signal S4, the pipelines 63 to 70 to which the hydraulic pressure signals S1 to S4 are sent are reconnected. The circuit arrangement can be switched with, and a large-scale device or a complicated mechanism is not required for the switching.

Further, in the second embodiment, the hydraulic pressure circuit is supplied with the first hydraulic pressure signal S1, the second hydraulic pressure signal S2, the third hydraulic pressure signal S3, and the fourth hydraulic pressure signal S4. Since the selector valve 56 for connecting 70 to each other is provided, and the circuit arrangement at the normal position and the circuit arrangement at the reverse position can be switched by switching the selector valve 56, the conduits 63 to 70 can be connected to each other. The mechanism for switching the connection is simpler and the switching operation is easier.

Further, in the second embodiment, the operator seat 54 is provided in the driver's seat 6 so that it can be reversed in the front-rear direction. It can be carried out.

Further, in the second embodiment, the operator seat 54 is rotatably attached to the driver's seat 6 via the turntable 55, and the reversal of the operator seat 54 in the front-rear direction is interlocked with the switching of the selector valve 56. The operator seat 54 can be inverted back and forth by rotating the turntable 55, and the inversion operation is simple. Moreover, since the operator seat 54 is interlocked with the selector valve 56, the circuit arrangement can be switched by simply reversing the operator seat 54.

Therefore, also according to the second embodiment described above, the driver can intuitively and comfortably perform the driving operation even when the driver reverses and drives the vehicle.

The hydraulic circuit type traveling operating device and operating method of the present invention, and the construction machine using the same are not limited to the above-described embodiments, but various modifications can be made without departing from the scope of the present invention. Of course, it can be added.

2 Body 3 Traveling device (crawler)
3A Left side traveling device (left side crawler)
3B Right side traveling device (right side crawler)
5 Operation device 6 Driver's seat 7 Pilot valve 7a Valve body (front valve body)
7b Valve body (rear valve body)
7c Valve body (Left valve body)
7d valve body (right valve body)
8 Control lever 54 Operator seat 55 Turntable 56 Selector valve 63 Pipe line 64 Pipe line 65 Pipe line 66 Pipe line 67 Pipe line 68 Pipe line 69 Pipe line 70 Pipe line 71 Pilot valve 71a Valve body (right front valve body)
71b Valve body (front left valve body)
71c valve body (valve body on the left rear)
71d Valve body (Rear right valve body)
100 Construction Machinery (Crawler Carrier)
S1 First hydraulic signal S2 Second hydraulic signal S3 Third hydraulic signal S4 Fourth hydraulic signal

Claims (8)

A hydraulic circuit type traveling operation device for operating, in a forward direction and a backward direction, of a traveling device provided on the left and right of a vehicle body through an hydraulic circuit from an operating device provided in a driver's seat,
The hydraulic circuit is
The left traveling device of the traveling devices is driven in the forward direction by the first hydraulic signal input to the hydraulic circuit, while being driven in the reverse direction by the third hydraulic signal input to the hydraulic circuit,
The right traveling device of the traveling devices is driven in the forward direction by the second hydraulic signal input to the hydraulic circuit, and is driven in the backward direction by the fourth hydraulic signal input to the hydraulic circuit. Normal circuit layout,
The left side traveling device is driven in the forward direction by the second hydraulic signal, while being driven in the reverse direction by the fourth hydraulic signal,
The right-side traveling device is configured to be switchable between a circuit arrangement in a reverse position, which is driven in the forward direction by the first hydraulic signal and is driven in the reverse direction by the third hydraulic signal. A hydraulic circuit type traveling operation device characterized in that: The operation device includes pilot valves in which four valve bodies are arranged at front, rear, left, and right positions with respect to the vehicle, and tilts of the operation lever in the front, rear, left, and right directions are input to the hydraulic circuit as hydraulic pressure from the four valve bodies. Is configured as
Of the four valve bodies, switching of the front valve body is input to the pipeline of the hydraulic circuit as the first hydraulic signal and the second hydraulic signal,
Of the four valve bodies, switching of the valve body on the rear side is input to the pipeline of the hydraulic circuit as the third hydraulic pressure signal and the fourth hydraulic pressure signal,
Of the four valve bodies, the switching of the left valve body is input to the pipeline of the hydraulic circuit as the second hydraulic pressure signal and the third hydraulic pressure signal,
The switching of the right valve main body of the four valve main bodies is configured to be input to the pipeline of the hydraulic circuit as the first hydraulic pressure signal and the fourth hydraulic pressure signal. Item 2. A hydraulic circuit type traveling operation device according to Item 1. The operating device includes pilot valves in which four valve bodies are arranged at right front, left front, left rear, and right rear positions with respect to the vehicle, and the tilting of the operating lever in the front, rear, left, and right directions is performed by hydraulic pressure from the four valve bodies. Is configured to input to the hydraulic circuit as
Of the four valve bodies, the switching of the right front valve body is input to the pipeline of the hydraulic circuit as the first hydraulic signal,
Of the four valve bodies, switching of the front left valve body is input to the pipeline of the hydraulic circuit as the second hydraulic signal,
Of the four valve bodies, the switching of the valve body on the left rear is input to the pipeline of the hydraulic circuit as the third hydraulic signal,
The hydraulic pressure according to claim 1, wherein among the four valve bodies, the switching of the valve body on the rear right side is configured to be input to the pipeline of the hydraulic circuit as the fourth hydraulic signal. Circuit type travel control device. The hydraulic circuit is provided with a selector valve that connects the pipelines to which the first hydraulic pressure signal, the second hydraulic pressure signal, the third hydraulic pressure signal, and the fourth hydraulic pressure signal are input.
The hydraulic arrangement according to any one of claims 1 to 3, wherein the circuit arrangement at the normal position and the circuit arrangement at the reverse position are configured to be switchable by switching the selector valve. Circuit type travel control device. The hydraulic circuit type traveling operation device according to any one of claims 1 to 4, wherein the driver's seat is provided with an operator seat that can be reversed in the front-rear direction. The operator seat is rotatably attached to the driver's seat via a turntable, and the inversion of the operator seat in the front-rear direction is configured to interlock with switching of the selector valve. The hydraulic circuit type traveling operation device according to claim 5. A construction machine to which the hydraulic circuit type traveling operation device according to any one of claims 1 to 6 is applied. A method for operating a hydraulic circuit type traveling operating device, wherein driving of a traveling device provided on the left and right of a vehicle body in a forward direction and a backward direction is operated via an hydraulic circuit from an operating device provided in a driver seat,
When the driver is seated frontward in the driver's seat, the left traveling device of the traveling devices is driven in the forward direction by the first hydraulic signal input to the hydraulic circuit, while The third hydraulic signal input to the circuit drives the vehicle in the reverse direction, and the right traveling device of the traveling devices drives the hydraulic circuit in the forward direction by the second hydraulic signal input to the hydraulic circuit. Drive in the reverse direction by the fourth hydraulic signal input to
When the driver is seated rearward in the driver's seat, the left-side traveling device is driven in the forward direction by the second hydraulic signal, while being driven in the reverse direction by the fourth hydraulic signal, The operating method of the hydraulic circuit type traveling operation device, wherein the right side traveling device is driven in the forward direction by the first hydraulic signal and is driven in the reverse direction by the third hydraulic signal.

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