JPH0537301Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to a load-sensing electric joystick that is applied to an operating lever of a hydraulic excavator, a crane truck, etc., for example.

[Conventional technology]

In conventional hydraulic excavators or crane trucks, the bucket, crane, etc. are operated by switching the so-called hydraulic pilot valve installed in the driver's seat.
The pilot pressure oil was used to switch hydraulic switching valves and operate buckets, cranes, etc.

[The problem that the idea attempts to solve]

The conventional hydraulic excavators, crane trucks, etc. mentioned above have the following problems to be solved.

That is, taking a hydraulic excavator as shown in FIG. 3 as an example, the operator operates a control lever (not shown) to control the boom cylinder 24 and arm cylinder 2.
5. By appropriately controlling the amount of expansion and contraction of the bucket cylinder 26, the boom 21, the arm 22, and the bucket 23 are operated to perform arbitrary work. However, for the operator, bucket 23, arm 2
2. Since it is not possible to directly sense the amount of load on the boom 21, the load condition is usually determined based on the movements of the bucket 23, arm 22, and boom 21, or fluctuations in the rotation of the prime mover. For example, underwater drilling, deep hole drilling, etc.
When the operator cannot directly see the movement of the bucket 23, there is a problem in that excavation efficiency is poor because it is impossible to judge how external force is applied. In addition, with the conventional hydraulic pilot operation method, it is necessary to lead the hydraulic pressure into the operator's cabin, and there are problems such as measures to strengthen the air conditioning to prevent the room temperature from rising due to the rise in oil temperature, oil leaks, and noise countermeasures to prevent the sound of oil flowing. It was hot.

[Means to solve the problem]

The present invention aims to provide an electric joystick shown in the following (1) and (2) as a means for solving the above problems.

(1) Equipped with a rod that converts rotational motion generated by a handshake operation into linear motion, a magnet installed in the rod, and an electromagnetic coil surrounding the magnet that can change the current value. An electric joystick that is characterized by the ability to

(2) The electric joystick according to (1) above, wherein the electromagnetic coil is an electromagnetic coil whose current value changes depending on the load of the actuator and which generates magnetic force in a direction that impedes movement of the rod.

[Effect]

Since the present invention is constructed as described above, it has the following effects.

In other words, when you operate (rotate) your handshake, that movement is replaced by a linear movement of the rod equipped with a magnet.
The rod reciprocates inside the electromagnetic coil. At that time, when the electromagnetic coil is energized, the rod is pushed or pulled by the repulsive or attractive force between the electromagnet and the magnet provided on the rod. Therefore, by passing current in the direction where the push and pull direction is the load in response to the handshake operation,
The operating force of the handshake becomes heavier, and the weight causes the operator to perceive a load.

The electromagnetic force is proportional to the magnitude of the current flowing through the electromagnetic coil, so if the current flowing through the electromagnetic coil is made to vary depending on the load pressure of a bucket hydraulic cylinder, for example, the pressure of the hydraulic cylinder that is proportional to the load will be the electromagnetic force. The operating force is changed as a result. That is, the operator will feel a large operating force in response to a large load.

〔Example〕

An electric joystick according to one embodiment of the present invention will be described with reference to Figs.

In addition, in Figures 1 and 2, handshake 1 is replaced by
When an operation is performed in either the X-axis or Y-axis direction in the figure, the shapes and actions of the components described below that respond to the operation are the same in both the X-axis direction and Y-axis direction, so the same reference numerals are used for both directions. , component parts that respond to operations in the X-axis direction are given a suffix a, and components that respond to operations in the Y-axis direction are given a b, and in order to avoid redundancy, particularly necessary except in case
The operation in the X-axis direction will be described as a representative example, and the Y-axis direction will be omitted.

In FIG. 1, when the operator operates the handshake 1, if the movement is, for example, in the +X direction of the sectional view shown in FIG.
rotates around the X-axis pin 17 and pushes the rod 6a downward via the X-axis spherical bush 15. In FIG. 1, a differential transformer 9a is used to output the lever operation signal, but a rotation type sensor that detects the rotation shaft may also be used. Rod 6
A core 10a for the actuating transformer 9a and a magnet 13a for repelling and attracting electromagnetic force are installed inside the rod 6a, and these are magnetically shielded from each other within the rod 6a. Furthermore, a magnetic shield plate 11a is provided between the actuating transformer 9a and the electromagnetic coil 12a. The rod 6a and the X-axis spherical bushing 15 are operated by return springs 7a and 8a.
A handshake 1 operated in the X direction or -X direction is returned to neutral. For operation in the +Y direction, the rod 6a is rotated around the Y-axis pin 16 and pulled up or pushed down via the Y-axis spherical bushing 19.
In addition to the above configuration, in FIG. 1, 3 is a soft boot that covers the rod 2 so as not to restrict its movement, 4 is a boot mounting screw that fixes the boot 3 to the case 5, and 5 is a case. FIG. 4 shows an example in which the electric joystick of the above embodiment is applied to the bucket cylinder 26 of the hydraulic excavator shown in FIG. The signal is converted and inputted to a switching valve drive amplifier 31 and a coil drive amplifier 32 via a lead wire 14 shown in FIG. The operating transformer signal 34 input to the switching valve drive amplifier 31 is converted into a switching valve drive signal 38 that drives the electro-hydraulic switching valve 33, thereby driving the electro-hydraulic switching valve 33 and the hydraulic pump 27.
Pressure oil is supplied to the bottom side or rod side of the bucket cylinder 26 through the electro-hydraulic switching valve 33, and the bucket cylinder 23 shown in FIG. 3 moves to perform an initial operation. When the handshake 1 is not operated and there is no switching valve drive signal 38, oil from the hydraulic pump 27 flows into the tank 28 through the electrohydraulic switching valve 33.
When the bucket 23 receives a load on hard ground, the pressure on the bottom side of the bucket cylinder 26 increases.
Since the cylinder bottom sensor 29 and cylinder rod pressure sensor 30 for pressure detection are installed in advance on the bottom side and rod side of the bucket cylinder 26, when the pressure on the bottom side changes, the detected cylinder bottom Pressure sensor signal 3
5 is input to the coil drive amplifier 32. The coil drive amplifier 32 receives the input cylinder bottom pressure sensor signal 35 and the differential transformer signal 34 for determining the handshake 1 operation direction, so it is difficult to determine in which direction the current should flow through the electromagnetic coil 12a. Can be distinguished. Additionally, it can also be determined whether the device is being operated or not. Based on these two signals, the coil drive amplifier 32 converts the coil excitation signal 37 into an arbitrary curve, which will be described later, by passing a current having a magnitude as set in advance in FIG.
, can be given as the operating force. The coil excitation signal 37 is input to the electromagnetic coil 12a through the lead wire 14. The coil drive amplifier 32 is set so that if the handshake 1 is reversed, a similar effect is performed by the cylinder rod pressure sensor 30 on the rod side. Reference number 36 is a cylinder rod pressure sensor signal. The graph in Figure 5 shows the relationship between the work equipment load (pressure sensor signal) and the operating force.The graph in Figure 5 shows the relationship between the work equipment load (pressure sensor signal) and the operating force. improvement can be measured. The above is an example of the operation in the X-axis direction in FIG. 1, but the Y-axis direction may be similarly applied to the arm cylinder 25 of the arm 22 or the boom cylinder 24 of the boom 21 in FIG. The choice is yours. Further, in order to reduce the cost of the electric joystick, it is also possible to use only the X-axis direction.

As described above, according to this embodiment, the reaction force against the handshake 1 due to electromagnetic force increases according to the load of the work machine, and
By correspondingly increasing the operating force of the handshake 1, for example, the hydraulic pressure applied to the bucket cylinder 26 is increased, thereby ensuring proper excavation. That is, even in cases such as underwater excavation where the bucket 23 cannot be directly seen, there is an advantage that the magnitude of the load can be perceived by the operational feel of the handshake 1, and the same effect as visual inspection can be achieved.

In addition, there is no need to install a hydraulic line in the cab for the electric joystick.
This has the advantage that there is no problem of temperature rise in the driver's cabin due to hydraulic heat, and problems such as oil leakage and pressure oil noise do not occur.

[Effect of idea]

Since the present invention is configured as described above, it has the following effects.

(1) By feeding back the load on the work equipment to the operating force, it is possible to feel the load state of the work equipment when underwater or deep trench excavation, and work efficiency can be improved.

(2) Compared to hydraulic joysticks, it generates less heat, vibration, and noise.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view of an electric joystick according to an embodiment of the invention, and FIG. 2 is a -
3 is an overall view of a general hydraulic excavator to which the above embodiment is applied, FIG. 4 is a system diagram of a hydraulic excavator bucket cylinder to which the electric joystick of the above embodiment is applied, and 5 This figure is a diagram showing the relationship between the work machine load and the handshake operation force in FIG. 4. 1...shake, 2...rod, 3...boots, 4
...Boot mounting screw, 5...Case, 6a, 6b
... Rod, 7a, 7b ... Return spring, 8
a, 8b...Return spring, 9a, 9b...Differential transformer, 10a, 10b...Core, 11
a, 11b...Magnetic shield plate, 12a, 12b
...Electromagnetic coil, 13a, 13b...Magnet, 14
... Lead wire, 15 ... X-axis spherical bushing, 16
...Y-axis pin, 17...X-axis pin, 18...Block, 19...Y-axis spherical bushing, 21...Boom, 22...Arm, 23...Bucket, 24...
...Boom cylinder, 25...Arm cylinder, 2
6...Bucket cylinder, 27...Hydraulic pump,
28...Tank, 29...Cylinder bottom pressure sensor, 30...Cylinder rod pressure sensor, 31
...Switching valve drive amplifier, 32...Coil drive amplifier, 33...Electrohydraulic switching valve, 34...Differential transformer signal, 35...Cylinder bottom pressure sensor signal, 36...Cylinder rod pressure sensor signal, 3
7...Coil excitation signal, 38...Switching valve drive signal.

Claims (1)

[Claims for Utility Model Registration] (1) A rod that converts rotational motion caused by a handshake operation into linear motion, a magnet provided on the rod, and a current value provided surrounding the magnet that is changed. An electric joystick characterized in that it is equipped with an electromagnetic coil. (2) The electric joystick according to claim 1, wherein the electromagnetic coil is an electromagnetic coil whose current value changes depending on the load of the actuator and which generates magnetic force in a direction that impedes the movement of the rod. .