JPH0620902U - Control circuit of control valve - Google Patents

Abstract

(57) [Summary] [Purpose] Since the flow characteristics of the control valve are constant with respect to the lever operation amount, there were cases where sufficient inching performance could not be obtained in work requiring inching performance. It is an object of the present invention to provide a control circuit that can obtain control performance that matches the movement of the operating lever. [Structure] An electric operation lever 1 that generates an electric signal E (θ) corresponding to an operation amount θ, and a required flow rate Q is calculated corresponding to an input E (θ) from the electric operation lever 1 to calculate an electric oil. The control valve 3 includes a controller 2 that outputs a flow rate command signal E (Q), and an electro-hydraulic control valve 3 that supplies a flow rate Q to an actuator 4 in response to the input of E (Q). The flow rate characteristic of the electro-hydraulic control valve 3 can be changed according to the input by the input method Δθ / Δt.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a control circuit for a control valve such as a hydraulic excavator. More specifically, the present invention relates to a control circuit that can obtain control performance that matches how to move the operating lever.

[0002]

[Prior art]

Generally, the operator's lever operation includes a fast operation area A for achieving a predetermined cylinder speed as shown in FIG. 6 and an inching operation area B for delicately controlling the load fluctuation and attachment attitude at the cylinder speed. On the other hand, as shown in FIG. 7, the flow characteristic of the control valve has an inching area C in which the flow rate Q changes little and an area D in which the flow rate changes greatly with respect to the operation amount θ of the operating lever. In this case until the operation amount of theta ₁ through? ₂ of the operating lever with respect to such operations Figure 6 is inching region of the valve can be used, so that the use of large areas of the flow rate variation when the operation amount is ₂ or more theta Therefore, in the case of the operation of FIG. 6 after all, the flow rate characteristic as shown in FIG. 8 was obtained and sufficient inching performance was not obtained after the time T ₂ .

[0003]

[Problems to be solved by the device]

 Since the flow rate characteristic of the control valve is constant with respect to the operation amount of the lever, sufficient inching performance may not be obtained in work that requires inching performance. It is an object of the present invention to provide a control circuit that can obtain control performance that matches the operation lever operation method.

[0004]

[Means for Solving the Problems]

 The electric operation lever 1 that generates an electric signal E (θ) corresponding to the operation amount θ, and the required flow rate Q corresponding to the input E (θ) from the electric operation lever 1 are calculated, and the electric oil control valve 3 The controller 2 which outputs a flow rate command signal E (Q) to the actuator 2 and the electro-hydraulic control valve 3 which supplies the flow rate Q to the actuator 4 in response to the input of E (Q). The flow characteristic of the electro-hydraulic control valve 3 is changed according to the input by θ / Δt (where θ: manipulated variable, t: time).

[0005]

【Example】

 FIG. 1 shows the circuit structure of the present invention. The electric operation lever 1 that generates an electric signal E (θ) corresponding to the operation amount θ, and the required flow rate Q corresponding to the input E (θ) from the electric operation lever 1 are calculated, and the electric oil control valve 3 is calculated. On the other hand, a controller 2 that outputs a flow rate command signal E (Q) and an electro-hydraulic control valve 3 that supplies a flow rate Q to an actuator 4 such as a cylinder according to the input of E (Q).

The controller 2 executes the following calculations. (1) From the signal E (θn) from the electric operation lever 1 at a certain time Tn, the operation amount θn determined by the electric operation lever output characteristic of FIG. 2 is calculated. (2) the _(Tn-1) of the operation amount from Shitaenu- ₁ by the following equation △ θn / △ tn the calculation. Δθn / Δtn = θn-θn- ₁ / Tn-Tn- _{1 (3) Calculate the flow gain Gn from the predetermined flow gain function f (} Δθ _{/ Δt) from} Δθn / Δtn _{(Fig. 3 reference). (4) From} the flow rate Qn- ₁ commanded to the control valve of the _{previous time (Tn- 1} ), calculate the commanded flow rate this time from the following equation. Qn = Gn × (θn-θn- ₁ ) + Qn- ₁ (5) Calculate the command signal E (Qn) corresponding to Qn from the output characteristics of the electric oil control valve 3 (Fig. 4), and Send an electric signal.

[0007]

[Operation of the embodiment]

The operation will be described by operating the electric lever in FIG. At the time of To, θo = 0 and the flow rate Qo = 0. Also, To = 0. At the time of T ₁ , Δθ ′ ₁ / Δt ₁ = θ ₁ / T ₁ , the flow rate gain G ₁ = f (θ ₁ / T ₁ ), and therefore Q ₁ = G ₁ × θ ₁ T ₂ At the time point, Δθ ₂ / Δt ₂ = θ ₂ −θ ₁ / T ₂ −T ₁ , the flow rate gain G ₂ = f (θ ₂ −θ ₁ / T ₂ −T ₁ ), and therefore Q ₂ = At the time of G ₂ (θ ₂ −θ ₁ ) + Q ₁ T ₃ , Δθ ₃ / Δt ₃ = θ ₃ −θ ₂ / T ₃ −T ₂ , and the flow rate gain at this time G ₃ = f (θ ₃ −θ ₂ / T ₃ −T ₂ ), therefore Q ₃ = G ₃ (θ ₃ −θ ₂ ) + Q ₂ where the flow gain function f (Δθ / Δt) is an increasing function as shown in FIG. if 6 Lee Nchingu region B in於Ru △ θ / △ t is the same, it becomes substantially the same flow rate characteristics and operation state of FIG. 6 as shown in FIG. 5, even at the T ₂ after it is inching operation.

In this description, Δθ / Δt is obtained by calculation, but a method of directly detecting it by using a sensor for detecting the rotation speed on the operation lever may be used.

[0009]

【effect】

 An electric operating lever that generates an electric signal E (θ) corresponding to the manipulated variable θ, and a required flow rate Q corresponding to the input E (θ) from the electric operating lever are calculated, and a flow rate is supplied to the electric oil control valve. The controller outputs the command signal E (Q) and the electro-hydraulic control valve that supplies the flow rate Q to the actuator in response to the input of E (Q). When the lever operation is slow, the flow rate also increases and decreases slowly, so that the operator feels as he or she wants.

[Brief description of drawings]

FIG. 1 is a control circuit diagram of a control valve according to the present invention.

FIG. 2 is an operation amount θ of an electric operation lever and an input signal E (θ)
FIG. 6 is a diagram showing the relationship between the output characteristic of the electric control lever and

FIG. 3 is a graph showing the relationship between the operation speed Δθ / Δt of the electric operation lever and the flow rate gain G.

FIG. 4 is a diagram showing a relationship between an input signal E (Q) and a flow rate Q, that is, an output characteristic diagram of an electric oil control valve.

FIG. 5 is a graph showing the relationship between time T and flow rate Q according to the present invention.

FIG. 6 is a graph showing the relationship between time T and manipulated variable θ.

FIG. 7 is a graph showing the relationship between the manipulated variable θ and the flow rate Q in the conventional technique.

FIG. 8 is a graph showing the relationship between time T and flow rate Q in the related art.

[Explanation of symbols]

 1 Electric control lever 2 Controller 3 Electro-oil control valve 4 Actuator

Claims (1)

[Scope of utility model registration request] 1. An electric operation lever (1) for generating an electric signal E (θ) corresponding to an operation amount θ, and a required flow rate (Q) corresponding to an input E (θ) from the electric operation lever (1). ) To output a flow rate command signal E (Q) to the electro-hydraulic control valve (3), and E
It is composed of an electro-hydraulic control valve (3) which supplies a flow rate (Q) to an actuator (4) according to an input of (Q), and an input method of an operation lever (1) Δθ / Δt (where θ: operation A control circuit for a control valve, characterized in that the flow rate characteristic of the electro-hydraulic control valve (3) can be changed according to the input by the amount, t: time.