JP2535868Y2 - Inertial control system for hydraulic equipment - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inertial body control device for hydraulic equipment, and more particularly to an inertial body control device for reducing an impact when the inertial body is decelerated.

[0002]

2. Description of the Related Art A conventional inertial body control device used for a large hydraulic device such as a hydraulic excavator will be described with reference to FIG.
As shown in the figure, the hydraulic pump 1 and the two main lines 2 and 3 are connected via a directional control valve 4, and the two main lines 2 and 3 are connected to a hydraulic motor 5. Switching of the direction control valve 4 is performed by an operation lever 7 of an operation unit 6, and an inertial body 8 is provided.
Can be rotated forward, backward and stopped. Also, two relief valves 9 and 10 are provided and connected to the two main lines 2 and 3, respectively, and the bypass lines 11 and
12 are formed.

In FIG. 1, when the operating lever 7 is turned in the direction of arrow A, the direction control valve 4 is switched from the neutral "closed" position C to the position B, and the one main pipeline 2 and the hydraulic pump 1 are connected. The hydraulic motor 5 is rotated in one direction by the communication, and the inertial body 8 is driven. When the operating lever 7 is returned to the neutral position, the direction control valve 4 returns to the "closed" position C, and the drive of the hydraulic motor 5 is stopped.

[0004]

In the conventional inertial body control device described above, when the operating lever is returned to the neutral position and the directional control valve is switched to the "closed" position in order to stop the driven inertial body. The inertial body rotates by inertia until it stops while decelerating. With this rotation, the hydraulic motor is rotated, and the pressure oil is pressure-fed to one of the main pipelines, the pressure rises sharply, and an impact is generated.

In order to prevent the occurrence of an impact, the operating lever must be very gradually operated in accordance with the inertia of the inertial body to suppress the rise in the pressure of the return-side main pipe. It takes time and is not feasible at the work site. Therefore, during a normal stop operation, regardless of the rotation speed of the operation lever, there is almost no change in the time required for the pressure of the return-side main pipeline to rapidly rise and reach the set pressure of the relief valve, and the operation lever is not operated. Since there is no correspondence between the movement and the time until the inertial body stops, there is a problem in the operational feeling.

Accordingly, there arises a technical problem to be solved in order to improve the operability by enabling rapid deceleration or gentle deceleration operation by making the inertial body correspond to the operation of the operation lever. Aims to solve this problem.

[0007]

SUMMARY OF THE INVENTION This invention is proposed to achieve the above-mentioned object. In a hydraulic device for driving an inertial body by a hydraulic motor, the hydraulic device is connected to two hydraulic oil ports of the hydraulic motor. The two connected main pipelines are connected via an electromagnetic switching valve, and a displacement sensor for detecting a drive operation amount of the operation unit, a rotation speed sensor for detecting a rotation speed of the hydraulic motor, an operation speed of the operation unit, Comparing means for comparing the reference operation speed set in the deceleration direction, and a required back pressure of the main line for obtaining a braking force corresponding to the deceleration operation amount, and calculating a feedback-side main line from the output of the rotation speed sensor. The hydraulic oil flow rate is calculated, and the opening area of the electromagnetic switching valve for obtaining the required back pressure is calculated from the operation amount of the operation unit, the feedback-side opening area of the directional control valve interlocked with the operation unit, and the hydraulic oil flow rate. Arithmetic means;
It is an object of the present invention to provide an inertial body control device in a hydraulic device comprising output means for outputting the calculation result as a control signal to the electromagnetic switching valve.

[0008]

According to the present invention, a displacement sensor detects an operation amount of an inertial body of an operation section such as an operation lever. The comparing means determines whether the operation unit is in any one of the neutral position, acceleration, steady speed, and deceleration based on the operation amount and the change speed thereof. When the deceleration operation is performed, the operation speed is compared with a preset reference operation speed. When the operation speed is lower than the reference operation speed, the flow rate of the return-side main pipeline of the hydraulic motor is calculated by the rotation speed sensor. Further, an appropriate brake pressure for the speed of the inertial body, that is, a required back pressure of the return-side main line is obtained from the operation amount. The required opening area of the electromagnetic switching valve connecting the two main pipelines is calculated from the return side opening area of the directional control valve interlocked with the operation, the flow rate and the required back pressure, and a control signal is sent to the electromagnetic switching valve. Is output.

When the deceleration operation is performed gradually, the electromagnetic switching valve is opened corresponding to the operation amount to communicate the two main lines, and the pressure in the return side main line is controlled to suppress a rapid pressure rise. Therefore, the occurrence of an impact during the deceleration operation is prevented. Also, the opening area of the electromagnetic switching valve changes to generate a back pressure of the return-side main line corresponding to the operation amount, that is, a brake pressure.
%, The electromagnetic switching valve is closed to keep the inertial body stationary.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below in detail with reference to the drawings. In FIG. 1, reference numeral 31 denotes a hydraulic pump. The hydraulic pump 31 is connected to a directional control valve 32 having three positions and four ports, and the directional control valve 32 and the hydraulic motor 33 are connected to two main lines 34 and 3.
5 to control the forward rotation, reverse rotation and stop of the hydraulic motor 33. The direction control valve 32 is controlled by an operation lever 37 provided on an operation unit 36. Hydraulic motor 33
Is connected to an inertia body 38 such as a swing body of a hydraulic shovel to drive the inertia body 38. Further, two relief valves 39, 40 are arranged between the main lines 34, 35 to form the main lines 34, 35.
The one relief valve 39 bypasses the hydraulic oil from the main line 34 to the other main line 35 when the oil pressure in the main line 34 exceeds a set value, and the other relief valve 40 has a reverse pressure difference. The other main line 35 to one main line 3
4. Bypass hydraulic oil to 4.

The inertial body control device includes a displacement sensor 41 for detecting the operation amount of the operation lever 37, a rotation speed sensor 42 for detecting the rotation speed of the hydraulic motor 33 or the inertia body 38,
Two-port two-position normally closed electromagnetic switching valve 43 and control device 4
The ports of the electromagnetic switching valve 43 are connected to the main pipelines 34 and 35, respectively. The electromagnetic switching valve 43 communicates with the main pipelines 34 and 35 during a so-called inching operation for gradually returning the operation lever 37 to the neutral position, and suppresses a sudden increase in pressure in the return-side main pipeline, thereby preventing the occurrence of an impact. .

FIG. 2 shows a change in the amount of operation of the operation lever 37. C indicates a change speed during rapid deceleration, and D indicates a change speed that gradually returns to the neutral position. Therefore,
The reference operation speed X ₀ for operating the above-described electromagnetic switching valve 43 is set to be lower than the change speed C during rapid deceleration, and this reference operation speed X ₀ is stored in the storage unit 45 of the control device 44. .

The storage unit 45 receives the operation program data shown in FIGS. FIG. 3 shows the correlation between the operation amount θ of the operation lever 37 and the brake pressure P ₀ for stopping the inertia body 38, that is, the back pressure of the main pipelines 34 and 35 depending on the opening degree of the electromagnetic switching valve 43. 3
When the position 7 is in the neutral position, the electromagnetic switching valve 43 is closed, the brake pressure P ₀ becomes 100%, and the idle rotation of the inertia body 38 is prevented by the hydraulic equilibrium of the main pipelines 34 and 35.

FIG. 4 is a correspondence table between the operation amount θ of the operation lever 37 and the return opening area A ₁ of the directional control valve 32 interlocked with the operation amount θ. FIG. a correspondence table of the opening area a ₂ of the switching valve 43. Next, the operation of the inertial body control device will be described with reference to the timing chart of FIG. 6 and the flowcharts of FIGS.
First, when the hydraulic device is started (step 101), the operation amount θ of the operation lever 37 and the rotation speed N of the hydraulic motor 33 are read from the outputs of the displacement sensor 41 and the rotation speed sensor 42 (step 101). If the operation lever 37 is in the neutral position, the process proceeds from step 103 to step 111, where the control signal ic is set to zero, and the electromagnetic switching valve 43 is set to the "closed" position C.
And the brake pressure is 100%.

Next, when the operation lever 37 is rotated to drive the inertial body 38 as shown at a time point E → F in FIG. 6, since the operation amount change speed dθ / dt ≧ 0 of the operation lever 37, step The process proceeds from step 104 to step 111, where the control signal i
Let c = 0. Subsequently, when the operation amount 37 is returned toward the neutral position, dθ / dt <0, and the process proceeds from step 104 to step 105. Here, the absolute value of dθ / dt is compared with the above-mentioned reference operation speed X _0, and when a rapid deceleration operation at or above the reference operation speed X ₀ as shown in FIG.
Proceed to 1 to set the control signal ic to zero and set the brake pressure to 1
00%.

[0016] On the other hand, to return to the gentle neutral position the operating lever 37 as shown in FIG. 6 at the reference operation speed X ₀ following rate (F → G), step 106 from step 105
Proceed to. In step 106, the arithmetic unit 46 sets the hydraulic motor 3
The flow rate Q ₀ is calculated by multiplying the number of revolutions N of 3 and the amount of pressure oil absorption g of the hydraulic motor 33. Te is at the next step 107, the feedback side opening area A ₁ in FIG. 3 and the direction control valve 32 from the operation amount θ of the operating lever 37 based on the correspondence table shown in FIG. 4, the required brake pressure P ₀ Is read. Then, the flow rate Q _0, calculates a required opening area A ₂ of the electromagnetic switching valve 43 from the value of the opening area A ₁ and the brake pressure P _0. This operation is represented by the following equation.

[0017]

(Equation 1)

Q ₀ is the total oil amount flowing to the return side main line 35 shown in FIG. 1, Q ₁ is the oil amount returning to the directional control valve 32,
Q ₂ is the amount of oil to flow to the electromagnetic switching valve 43, and P ₂ is the pressure in the return side main line 35. And from the above formula

[0019]

(Equation 2)

## EQU1 ## Then, the pressure P ₂ of the return side main line 35 is set to the brake pressure P _0.

[0021]

(Equation 3)

## EQU1 ## Next, determine the control signal ic that corresponds to the required opening area A ₂ of the electromagnetic switching valve calculated from the correspondence table shown in FIG. 5 (step 109), the output unit 47 outputs the control signal ic (step 110). Therefore, after the time point F shown in FIG. 6, the electromagnetic switching valve 43 is almost fully opened to suppress a rapid rise in the pressure of the return-side main line 35, and to reduce the brake pressure P ₀ corresponding to the operation amount of the operation lever 37 shown in FIG. In order to generate this, the valve is closed in proportion to the amount returned to the neutral position. At the neutral position, the valve is completely closed and the brake pressure P ₀ becomes 100%.

[0023] Thus, when performing deceleration operation at the reference operation speed X ₀ following rate, since communicates the two main lines 34 and 35, the abrupt pressure rise in the feedback side of the main conduit is generated And the impact due to pressure rise is prevented. The opening area of the electromagnetic switching valve 43 is reduced in conjunction with the operation amount, and a braking force proportional to the operation amount is obtained.
However, in the neutral position, the electromagnetic switching valve 43 is closed to smoothly stop the inertia body 38.

FIG. 9 shows another embodiment, in which the pressure sensors 5 are connected to the pilot lines 51, 52 of the directional control valve 32.
3 and 54 are provided to detect the operation amount of the operation lever 37 from the pressure change of the operation pilot lines 51 and 52. The present invention can be variously modified without departing from the spirit of the present invention, and it goes without saying that the present invention extends to those modifications.

[0025]

[Effects of the Invention] Since the present invention is configured as described in detail in the above embodiment, when gradually decelerating operation, a brake pressure is applied to the inertial body in accordance with the operation amount, and the impact is reduced. It is possible to smoothly reduce the speed without occurrence, and it is possible to reduce the degree of fatigue of the operator. In addition, the correlation of the inertial body motion with the deceleration operation is improved, and the operational sensation is significantly improved, and fine control of the stop position, which was difficult in the past, can be performed. It is a practical and valuable device to demonstrate.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an inertial body control device.

FIG. 2 is a graph showing a reference operation speed.

FIG. 3 is a graph showing a setting of a brake pressure with respect to a deceleration operation amount.

FIG. 4 is a graph showing a relationship between an operation amount of an operation lever and an opening area of a direction control valve.

FIG. 5 is a graph showing a relationship between an output of a control signal and an opening area of an electromagnetic switching valve.

FIG. 6 is a timing chart of the operation amount of the operation lever and the pressure of the main pipeline when the inertial body is operated.

FIG. 7 is a first half of a flowchart of the control device.

FIG. 8 is the latter half of the flowchart of the control device.

FIG. 9 is a configuration diagram of an inertial body control device showing another embodiment.

FIG. 10 is a configuration diagram of a conventional inertial body control device.

[Explanation of symbols]

31 hydraulic pump 32 directional control valve 33 the hydraulic motors 34, 35 main duct 36 operation unit 37 operating lever 38 an inertial body 41 displacement sensor 42 speed sensor 43 solenoid selector valve 44 controller 45 storage unit 46 operation unit 47 output unit X ₀ reference Operation speed

Claims (1)

(57) [Scope of request for utility model registration] In a hydraulic device for driving an inertial body by a hydraulic motor, two main pipelines respectively connected to two hydraulic oil ports of the hydraulic motor are connected via an electromagnetic switching valve, and an operation unit is provided. A displacement sensor for detecting a drive operation amount, a rotation speed sensor for detecting a rotation speed of the hydraulic motor, a comparison means for comparing the operation speed of the operation unit with a reference operation speed set in a deceleration direction, and a deceleration operation amount. Calculate the required back pressure of the main line to obtain the corresponding braking force, calculate the pressure oil flow rate of the return side main line from the output of the rotation speed sensor, and control the operation amount of the operation unit and the directional control linked to the operation unit. Calculating means for calculating the opening area of the electromagnetic switching valve for obtaining the required back pressure from the opening area on the feedback side of the valve and the pressure oil flow rate, and output means for outputting the calculation result as a control signal to the electromagnetic switching valve In hydraulic equipment consisting of Sex control device.