JPH0415781Y2 - - Google Patents

Description

[Detailed description of the invention] A. Purpose of the invention A. Industrial application field This invention relates to a hydraulic circuit for a snowplow.

B. Prior Art and Problems In existing snowplows, a hydraulic circuit is constructed as shown in FIG. 2 or 3 in order to change the speed of each hydraulic actuator.

Referring to FIG. 2, reference numeral 1 denotes a hydraulic pump rotated by an engine or the like, which normally has a constant discharge amount at a certain number of revolutions.

2 is an oil tank, and 3, 4, and 5 are electromagnetic directional valves, which may be manual or electric.

6 and 7 are hydraulic cylinders, 8 is a hydraulic motor, and each actuator uses a fixed throttle 9 or a semi-fixed throttle 10 to adjust the flow rate.

In the hydraulic circuit configured as described above, the speed cannot be changed arbitrarily, and since the pipe line is simply constricted, the excess flow is returned to the tank at the set pressure of the relief valve 11.
This is a very unreasonable circuit, as it results in a loss of power, and as that loss turns into heat, the oil temperature rises, necessitating the provision of an oil cooler.

Regarding FIG. 3, the electromagnetic directional switching valve 12 can control the flow rate by changing the hydraulic pressure and the amount of movement of the spool, and can also be operated manually or electrically, and the inlet valve block 13 controls the flow rate. Since the pressure is returned to the tank at a pressure of several kg/cm ² plus the load pressure, there is little power loss and it can be said to be an efficient circuit.

However, since the valve of the electromagnetic directional control valve 12 is currently very expensive, if it is prepared for each actuator, it is considered that the cost will increase considerably when it is incorporated into a product.

B. Structure of the invention A. Means for solving the problem The object of the present application is to provide a low-cost hydraulic circuit that can arbitrarily adjust the speed of each actuator and has little power loss.
In order to achieve the above purpose, the following configuration is adopted.

Hydraulic pump 1, electromagnetic directional valves 15, 16,
Electromagnetic flow control valve 1 with unload function in the middle of 17
One electromagnetic directional control valve 15, 16, 17 is provided.
By simultaneously operating the flow control valve 14 and the electromagnetic flow control valve 14 with an unloading function, the hydraulic direction and amount of oil can be adjusted.

The above simultaneous operation method is such that if the partner is an electromagnetic type, the electromagnetic directional control valve 1 is attached to the operating levers 18, 19, and 20.
The switches 21, 22, 23 for 5, 16, 17 and the operating angle detection sensor of the electromagnetic flow regulating valve with unloading function are installed, and a flow rate adjustment method proportional to the lever angle may be used. A method may also be used in which an operation angle detection sensor is attached, the lever operation speed is read by a controller, and the flow rate is adjusted in proportion to the lever speed, and these methods can be designed arbitrarily.

Further, if the electromagnetic directional switching valves 15, 16, 17 and the electromagnetic flow rate adjustment valve with unloading function 14 are manual types, they may be configured so that they can be operated simultaneously using cables.

(b) Examples of implementation of the idea Examples will be described with reference to the drawings.

FIG. 1 shows an embodiment of a device using the hydraulic circuit of the present invention, in which 1 is a hydraulic pump, 2 is an oil tank,
4 is an electromagnetic flow regulating valve with an unload function, which is connected to the hydraulic pump discharge port with a hydraulic hose;
Numerals 5, 16, and 17 are electromagnetic directional control valves, which are connected to the control flow discharge port of an electromagnetic flow regulating valve with an unloading function by hydraulic hoses, and 6 and 7 are hydraulic cylinders;
8 is a hydraulic motor, which is connected to each electromagnetic directional control valve with a hydraulic hose.

Further, control levers 18, 19, 20 are provided for each actuator, and the control levers 18, 19, 20 are provided with an electromagnetic directional control valve 15,
Switches 21, 22, 23 that turn on and off the electricity to drive the valves 16, 17, and potentiometers 24, 25, 26 that generate the voltage that controls the electromagnetic flow control valve 14 with unload function are installed, and the operation lever By tilting 18, 19, and 20, the ON-OFF switch works and the electromagnetic directional control valve 1
At the same time as the levers 5, 16, and 17 operate, a current proportional to the tilting angle at that time flows to the electromagnetic flow regulating valve 14 with an unloading function, so that the amount of oil proportional to the lever tilting angle is adjusted to the electromagnetic directional control valves 15, 16, and 17. 17
The oil flows to the actuator, and as a result, the operating direction and speed of the actuator corresponding to the operating levers 18, 19, 20 are obtained.

That is, the discharge flow generated by the hydraulic pump 1 reaches the electromagnetic flow regulating valve 14 with an unloading function via a hydraulic hose, and the controlled discharge amount and flow rate are controlled to the flow rate corresponding to the operating angle of the operating levers 18, 19, and 20. Divided into a reduced oil volume, i.e. surplus flow, for control purposes.

The controlled discharge flow discharged from the electromagnetic flow regulating valve 14 with an unloading function reaches the electromagnetic directional switching valves 15, 16, 17 via a hydraulic hose, and flows into the actuator corresponding to the operation of the operating lever.

Therefore, one electromagnetic flow regulating valve 14 with an unloading function can control the speed of three actuators.
That is, it becomes possible to control the flow rate of oil flowing into the actuator.

In addition, the surplus flow branched by the electromagnetic flow regulating valve 14 with an unloading function is several kg/cm 2 against the load pressure generated by the actuator operated from the inlet valve block of the electromagnetic flow regulating valve 14 with an unloading ^function. Since the added pressure is returned to the tank and does not pass through a normal relief valve, a highly efficient hydraulic circuit with less heat generation can be realized.

C. Effects of the invention In the device configured as described above, flow rate adjustment is not restricted as in the case of the hydraulic circuit shown in Figure 2, and moreover, surplus flow is efficiently returned to the tank. There is less loss of power, and the third
The entire device can be assembled at a lower cost than the circuit shown in the figure.

Furthermore, when the above configuration is introduced into a snow throwing device as shown in Fig. 4, the actuator cannot be stopped at a desired location due to the speed of the actuator being too fast to adjust the snow throwing position. It was often impossible to dump snow on the street, or it was too late, so that emergencies could not be reached in time.

However, according to the hydraulic circuit of the present invention, the speed of the actuator can be changed arbitrarily and easily, so that the snow throwing position can be adjusted quickly and accurately.

Although the above description has been made regarding a snow throwing device, it can be applied to various other devices that utilize hydraulic pressure, and can be described as a very useful device.

In the figure, 27 is a blower case, 28 is a hydraulic cylinder, 29 is a hydraulic motor, 30 and 31 are hydraulic cylinders, 32 is a cap elevation angle sensor, 33 is a cap, and 34 is a hydraulic cylinder, respectively.

[Brief explanation of the drawing]

FIG. 1 is a hydraulic circuit diagram of the present invention, FIGS. 2 and 3 are conventional hydraulic circuit diagrams, and FIG. 4 is a front view of a snow throwing device to which the hydraulic circuit of the present invention is applied. 1... Hydraulic pump, 2... Oil tank, 6, 7...
...Hydraulic cylinder, 8...Hydraulic motor, 14...Solenoid flow rate adjustment valve with unload function, 15, 16, 1
7... Solenoid directional control valve, 18, 19, 20... Operation lever, 21, 22, 23... Switch, 2
4, 25, 26...potentiometer.

Claims (1)

[Scope of utility model registration request] In a snowplow equipped with a plurality of hydraulic devices such as hydraulic cylinders 6, 7 and a hydraulic motor 8, the intermediate between the hydraulic pump 1 and the electromagnetic directional control valves 15, 16, 17 is used to move the plurality of hydraulic devices at a desired speed. An electromagnetic flow regulating valve 14 with an unloading function is provided in the flow control valve 14, and electromagnetic directional switching valves 15, 16, 17 are installed on the flow rate control discharge side of the electromagnetic flow regulating valve 14 with an unloading function,
The surplus flow discharge side of the electromagnetic flow regulating valve 14 with an unloading function is piped to the oil tank 2, and the operating levers 18, 1
Switches 21, 22, 23 for operating electromagnetic directional control valves attached to 9, 20 and potentiometers 24, 25, 2 for operating electromagnetic flow rate regulating valves with unload function.
6 is configured so that the tilting of the operating lever can be detected in two systems simultaneously, and by operating the electromagnetic directional control valves 15, 16, 17 and the electromagnetic flow rate adjustment valve with unload function 14 simultaneously by operating the lever, the hydraulic pressure is A hydraulic circuit for a snowplow, characterized in that the direction and oil amount can be adjusted.