JP3206929B2 - Travel straight circuit device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to, for example, a straight traveling circuit device for preventing traveling of a vehicle when a left and right traveling switching valve and other switching valves are simultaneously operated in various construction vehicles. Regarding improvement.

[0002]

2. Description of the Related Art A conventional straight traveling circuit device has, for example, a configuration as shown in FIG. First, there are hydraulic pumps 1 and 3 as a first hydraulic pump and a second hydraulic pump. On the discharge side of these hydraulic pumps 1 and 3, a right traveling switching valve 5 and a left traveling switching valve 7 are arranged. And,
Between the switching valve 5 for right traveling and the switching valve 7 for left traveling,
The switching valves 9, 11, and 13 other than the left and right traveling are arranged respectively.

A hydraulic pump 15 as a third hydraulic pump is arranged separately from the hydraulic pumps 1 and 3. On the discharge side of the hydraulic pump 15, switching valves 17, 19, 21 are arranged. On the secondary side of these switching valves 17, 19 and 21, a pilot operation switching valve 23 is arranged. The switching valves 5, 7, 9, 11, 13 are connected to sub switching valves 25, 27, 29, 31, 33, respectively.

A hydraulic pump 35 is used as a signal hydraulic source.
Is installed. The discharge side of the hydraulic pump 35, the pilot operation switching valve 23, the sub switching valves 25 and 27,
A signal path 37 is provided between the signal path 29, 31, and 33. Further, a tank 39 is provided.

The operation will be described based on the above configuration. For example, it is assumed that the switching valve 5 for right traveling and the switching valve 7 for left traveling are operated, and the other switching valves 9, 11, 13 on the discharge side of the hydraulic pumps 1, 3 are simultaneously operated. When the right-hand switching valve 5 and the left-hand switching valve 7 are actuated, the hydraulic oil supply passages 41 and 43 to the secondary side are shut off. Is not supplied to the other switching valves 9, 11 and 13.

On the other hand, when the other switching valves 9, 11, and 13 are operated, the sub switching valves 29, 31, and 33 are switched, and the signal passage 37 is shut off. To rise. The pilot operation switching valve 23 is switched by the increase in the pressure of the signal passage 37. By the switching of the pilot operation switching valve 23, the hydraulic oil from the hydraulic pump 15 is supplied to the other switching valves 9, 11, and 13 via the passage 45, thereby enabling straight traveling. ing.

In the case of an operation pattern other than that described above, the pilot passage switching valve 23 is not switched because the signal passage 37 is in communication with the tank 39.
Also, a switching valve 17 disposed on the discharge side of the hydraulic pump 15,
Reference numerals 19 and 21 denote switching valves 9 on the discharge side of the hydraulic pumps 1 and 3,
Since they are arranged independently of 11 and 13, traveling straight ahead is possible.

[0008]

According to the above-mentioned conventional configuration, there are the following problems. First, there is a problem that the configuration for enabling straight traveling is complicated, and many devices are required. That is, the hydraulic pump 35 as a signal hydraulic source is required, and the sub switching valves 25, 27, 29, 31, 33 for signal processing are required. In addition, each sub switching valve 25, 27, 29, 31,
Connecting the 33 to the switching valves 5, 7, 9, 11, 13 was also complicated.

SUMMARY OF THE INVENTION The present invention has been made based on such a point, and an object of the present invention is to provide a traveling straight traveling circuit device capable of traveling straight with a simple configuration with a small number of devices.

[0010]

To achieve the above object, a traveling straight traveling circuit device according to the present invention comprises a first hydraulic pump, a second hydraulic pump, a third hydraulic pump, and a discharge side of the first hydraulic pump. , A left traveling switching valve disposed on the discharge side of the second hydraulic pump, and a tank between the right traveling switching valve and the left traveling switching valve.
An arbitrary number of switching valves interposed in the dem, switching means disposed on the discharge side of the third hydraulic pump, and switching means;
And a signal path for guiding a switching signal.
In the lead circuit device, the signal means is the right running switch.
Neutral flow path of the switching valve, neutral flow path of the switching valve for left running, and
While connecting to the tank through the neutral flow path of the switching valve,
Connect each neutral flow path in parallel and switch
The means may include a third when the signal passage is opened to the tank.
The working fluid from the hydraulic pump is discharged to the tank side, and when the signal passage is shut off , the working fluid supplied from the third hydraulic pump is supplied to the switching valve side. .

[0011]

For example, when the signal passage is open to the tank, the working fluid supplied from the third hydraulic pump is discharged to the tank by the switching means. On the other hand, when the signal passage is interrupted by activating the switching valve for right traveling and the switching valve for left traveling and operating the switching valve, the switching means is activated to activate the switching means. (3) The working fluid supplied from the hydraulic pump is supplied to the switching valve. Thereby, straight traveling becomes possible. In the case of the present invention, unlike the related art, a hydraulic pump as a signal hydraulic power source is not required, and a sub-switching valve is connected to a right traveling switching valve, a left traveling switching valve, and any number of switching valves. It is not necessary to perform the above, and a desired function can be exhibited with a very simple configuration.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIG. The same parts as those in the related art are denoted by the same reference numerals, and description thereof is omitted. On the secondary side of the switching valve 21, a poppet valve 101 as switching means is inserted. From the poppet valve 101 to the switching valve 5 for right traveling and the switching valve 7 for left traveling, signal passages 103 and 105 are provided. The signal passages 103 and 105 communicate with the tank 39. The switching valves 9, 11, and 13 have a poppet valve 1.
One signal path 107 is connected in series with the tank 39 and communicates with the tank 39 via the switching valve 9.

The poppet valve 101 is provided with a hydraulic pump 15
Hydraulic oil supplied from the tank 3 through the passage 102
9 or through the passage 45, the switching valves 9, 11, 1
It is selectively distributed to the third side. That is, when the signal passages 103, 105, and 107 are open to the tank 39, the valve element 104 is connected to the coil spring 1
The hydraulic oil is pushed down against the spring force of 06 to discharge the hydraulic oil to the tank 39 through the passage 102. On the other hand, when the signal passages 103, 105, and 107 are shut off, the pressure rises to push up the valve body 104, shut off the passage 102 to the tank 39 side, and pass the hydraulic oil through the passage 45. This is supplied to the switching valves 9, 11, 13 side. Incidentally, reference numeral 108 in the drawing denotes an orifice.

The operation will be described based on the above configuration. When the right traveling switching valve 5 and the left traveling switching valve 7 are operated and the other switching valves 9, 11, 13 are activated, the signal passages 103, 105, 107 are shut off, and the poppet valve 101 is opened. Closes. As a result,
3 hydraulic oil from the hydraulic pump 15 via the passage 45, is supplied to the switching valve 9, 11, 13. Therefore , passage 4
5 is divided into a passage for supplying hydraulic oil to the switching valve 11 and the switching valve 13 and a passage for supplying hydraulic oil to the switching valve 9, and is supplied via a check valve provided upstream of each switching valve. You. That is, only the hydraulic oil of the first hydraulic pump is used for right running.
However, only the hydraulic oil of the second hydraulic pump is supplied for left running.
If the operation of the switching valve hinders straight running,
Absent.

Next, in the case of operation patterns other than those described above, at least one of the signal paths 103, 105 and 107 is in a state of communicating with the tank 39. The poppet valve 101 is opened, and the hydraulic oil from the third hydraulic pump 15 is discharged from the passage 102 to the tank 39, and is not supplied to the switching valves 9, 11, and 13. However, for example, the left traveling switching valve 7 is in the neutral position and the signal passage 10
3 is in communication with the tank 39, and the switching valves 11, 1
3 is switched, the hydraulic oil from the second hydraulic pump 3 is supplied to the switching valves 11 and 13 through the neutral flow path of the left traveling switching valve 7. That is, in such a case, not from the third hydraulic pump 15,
Hydraulic oil is supplied from the second hydraulic pump 3 to the switching valves 11 and 13. When the right traveling switching valve 5 is in the neutral position and the signal passage 105 is in communication with the tank 39, the hydraulic oil from the first hydraulic pump 1 receives the right traveling switching valve 5 in the neutral position.
It is supplied to the switching valve 9 through the flow path . In other words, drive right
In the state where the switching valve 5 for left and the switching valve 7 for left traveling are operated,
Unless the other switching valves 9, 11, 13 are operated,
The hydraulic oil supplied to the switching valves 9, 11, 13 is supplied to a third hydraulic pump.
Not from the pump, but from the second or first hydraulic pump
Will be done.

According to the present embodiment, the following effects can be obtained. First, the configuration for enabling straight traveling has been simplified. That is, unlike the related art, the hydraulic pump 35 (shown in FIG. 5) as a signal hydraulic power source is not required, and each of the switching valves 5, 7, 9, 11, 13 is provided with a sub switching valve 25, 27, 29. , 31, 33 (shown in FIG. 5) no longer need to be connected. Therefore, the apparatus can be made compact and cost can be reduced.

Further, by using the poppet valve 101, it is possible to further promote downsizing of the device. That is, in the case of the conventional pilot operation switching valve 23 (shown in FIG. 5), the hydraulic pump 15 (shown in FIG. 5)
This is because it is not possible to reduce the size of the spool and reduce the width of the pilot operation switching valve 23 because the entire amount of the hydraulic oil passes through the spool. On the other hand, in the case of the poppet valve 101, this is not the case, and the poppet valve 101 itself is compact.

Next, a second embodiment of the present invention will be described with reference to FIGS. In the case of this embodiment, an example is shown in which a spool type switching valve 109 having no area difference is used as the switching means. Signal paths 103, 105,
When the shutter 107 is not blocked, the spool 111 is urged to the right in the drawing against the spring force of the coil spring 113. Therefore, the hydraulic oil from the hydraulic pump 15 is discharged to the tank 39 via the notch passage 115 and the tank passage 117.

On the other hand, the signal paths 103, 105,
When the shutter 107 is shut off, the spool 111 moves to the left in the drawing, and shuts off the notch passage 115 and the tank passage 117. Therefore, the hydraulic oil from the hydraulic pump 15
It is supplied to the switching valves 9, 11, 13 via the passage 45 shown in FIG. Incidentally, reference numeral 119 in the drawing denotes an orifice. Therefore, the same effect as in the case of the first embodiment can be obtained.

Next, a third embodiment will be described with reference to FIG. This also uses another type of switching valve 120 as switching means. Also in this case, the signal path 103,
When the shutters 105 and 107 are not shut off, the spool 121 is urged to the right in the drawing against the spring force of the coil spring 123. Therefore, the hydraulic pump 1
The hydraulic oil from 5 is discharged to the tank 39 via the switching valve 120.

On the other hand, the signal paths 103, 105,
When the shutter 107 is shut off, the spool 121 moves to the left in the drawing, and shuts off the switching valve 120. Therefore, the hydraulic oil from the hydraulic pump 15 is supplied to the switching valves 9, 11, and 13 via the passage 45 shown in FIG.
Incidentally, reference numeral 125 in the drawing denotes an orifice. Therefore, also in this case, the same effects as those of the first and second embodiments can be obtained.

[0022]

As described in detail above, according to the straight traveling circuit device according to the present invention, straight traveling can be performed with a simple configuration including a small number of devices, and the device can be made compact and the cost can be reduced. be able to.

[Brief description of the drawings]

FIG. 1 is a diagram showing a first embodiment of the present invention and is a diagram showing a configuration of a straight traveling circuit device.

FIG. 2 is a cross-sectional view illustrating a configuration of a switching unit according to a second embodiment of the present invention.

FIG. 3 is a view showing a second embodiment of the present invention, and is a view taken along the line III-III of FIG.
It is an arrow view.

FIG. 4 is a diagram showing a third embodiment of the present invention, and is a diagram showing a configuration of a switching means.

FIG. 5 is a diagram showing a configuration of a conventional straight traveling circuit device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Hydraulic pump (1st hydraulic pump) 3 Hydraulic pump (2nd hydraulic pump) 5 Right traveling switching valve 7 Left traveling switching valve 9 Switching valve 11 Switching valve 13 Switching valve 15 Hydraulic pump (3rd hydraulic pump) 39 Tank 101 Poppet valve (switching means) 103 Signal path 105 Signal path 107 Signal path

Claims (1)

(57) [Claims] A first hydraulic pump, a second hydraulic pump,
A third hydraulic pump, a right traveling switching valve disposed on the discharge side of the first hydraulic pump, a left traveling switching valve disposed on the discharge side of the second hydraulic pump, and the right traveling switching valve And an arbitrary number of switching valves interposed in tandem between the switching valve for left traveling and the switching valve for left traveling, and disposed on the discharge side of the third hydraulic pump .
Switching means, and a signal for guiding a signal for switching the switching means
A traveling straight circuit device comprising:
The signal means is a neutral flow path for the right traveling switching valve, the left traveling
Through the neutral flow path of the row switching valve and the neutral flow path of the switching valve
While connecting to the tank,
Connected in parallel, and the switching means
Working fluid from the third hydraulic pump when released to the
Is discharged to the tank side, and when the signal passage is shut off ,
A traveling straight circuit device wherein a working fluid supplied from a third hydraulic pump is supplied to a switching valve side.