JPS58211024A - Acceleration control for variable slipping clutch - Google Patents

Abstract

PURPOSE:To prevent current value and lubricant temperature after cooling a clutch from exceeding limit values to accelerate rapidly a load to a set speed by limitting drive current for a motor while controlling lubricant temperature after cooling a clutch. CONSTITUTION:An input current detector 1a is provided at the side of voltage applied to a motor 1. A temperature detector 2a is provided at the outlet side of clutch lubricating oil of a slipping clutch 2. A rotational speed detector 1d takes out the rotational speed of an output shaft 1c for driving a load 3 through the variable speed slipping clutch 2 from the motor 1. To a min. value selector 7 are given the respective output signals of a current comparator 4, a temperature comparator 5 and a speed change comparator 6 to be compared with each other. The lowest signal value among these signals is taken out so that voltage signal is once converted to current signal by a V/I output circuit 8 and sent to an electricity-hydraulic pressure converter to control the clutch operating hydraulic pressure through a clutch hydraulic pressure controlling valve 9a.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an acceleration control device for a variable speed slipping clutch, and the load is accelerated by an electric motor via the variable speed slipping clutch.

Generally, when accelerating a load with an electric motor via a variable speed slipping clutch, depending on how the operating oil pressure of the slipping clutch is controlled, the lIA dynamic flow of the electric motor may become excessive, or the lubricating oil temperature may rise after cooling the clutch, causing the clutch This often results in burnout of the board. Figure 1 shows the changes over time in the motor drive current value, lubricating oil temperature after clutch cooling, etc. when control is not performed.
is the clutch oil pressure (Kt/ca) s I is the motor driving current (A), T is the lubricating oil temperature after clutch cooling ('
C) and N indicate the clutch output shaft rotational speed [r, p, m). In this way, when accelerating under a constant hydraulic pressure, the drive current value of the electric motor is generally as shown in Fig. 2. As shown in the curve, at the beginning, a large drive torque acts due to the increase in clutch oil pressure, so the increase continues until the first peak II)
, it decreases slightly, and then begins to increase again due to an increase in centrifugal oil pressure as the rotational speed of the output shaft of the clutch increases.
The peak value Ip of Ip decreases rapidly as the oil pressure decreases as it approaches a predetermined rotational speed, and finally reaches the predetermined rotational speed and stabilizes at a constant value Ic, but the power receiving equipment capacity and motor maintenance Also, from the viewpoint of energy saving, it is desirable to limit the peak value of the motor drive current value to a low value during load acceleration. Even if the clutch hydraulic pressure is controlled to increase linearly or in a curved manner as a preventive measure, a peak current will always occur somewhere and the other parts will be accelerated at a low current value, which will cause the clutch cooling part to Even if the rise in lubricating oil temperature can be prevented, there is a drawback that the electric function cannot be used effectively. Matakari Ki
ff, even if the clutch hydraulic pressure is controlled non-linearly to keep the flow value constant, it takes time to reach the specified speed when accelerating the load, and during that time the clutch continues to slip, generating frictional heat. However, there is a drawback that the clutch plate may burn out due to the rise in lubricating oil temperature when the clutch cooling section is busy. Taking these points into consideration, the present invention was developed from various viewpoints, and as a result, it is necessary to limit the driving current of the electric motor for effective and safe use of electric functional power during acceleration control to a set speed, and to prevent burnout of the clutch plate. This system also controls the temperature of the lubricating oil after cooling the clutch. For this purpose, an input current detector is installed on the electric motor, a rotation speed detector is installed on the output shaft of the clutch, and an oil temperature detector is installed on the outflow side of the lubricating oil for cooling the clutch, and the detection signals from each detector and these The current of the electric motor can be adjusted by comparing and calculating the respective values based on the set signals and inputting the optimal signal value calculated from these values to an electro-pneumatic-hydraulic converter or an electro-hydraulic converter to control the clutch operating oil pressure. A special feature is that the load is accelerated to the set speed as quickly as possible without the lubricating oil temperature after cooling the clutch exceeding the limit value. Next, a circuit block diagram of an embodiment of the device of the present invention is shown in FIG.

In the figure, 7 is a three-phase induction motor whose rotation is given to load 3 through a slipping clutch.

In addition, /a is an input current detector provided on the applied voltage side of the motor l, and this detection signal is converted into a voltage signal by the -tan I/V (current/voltage) conversion circuit /b, and then input to the current comparator S. It is compared with the limit current setting value given to the side and set in advance by the limit current setter IIa, and an electric signal proportional to the difference is extracted and applied to the minimum value selector. Next, a temperature detector core a is provided on the clutch lubricating oil outlet side of the slipping clutch core to detect the temperature of the lubricating oil after the clutch has been cooled. This detection signal is sent to the temperature/voltage conversion circuit.
2b converts it into a voltage signal and gives it to the input side of the temperature comparator 30, which is compared with the limit temperature setting value set in advance by the limit temperature setting device ka, and an electric signal proportional to the difference is extracted and set to the minimum value. be given to selector 7. Furthermore, the rotational speed of the output shaft /c which drives the load 3 from the electric motor l through the variable speed slipping clutch is detected by a pulse pickup type rotational speed detector /(1). The signal is converted into an electrical signal by the pressure) conversion circuit /f, and then compared with the speed setting signal given to the input side of the speed comparator 6 and preset by the speed setting device 6a, and an electrical signal proportional to the difference is extracted. This is also given to the minimum selector.
Toneri current comparator q1, temperature comparator S,
Each output signal of the speed comparator B is given and compared, and the lowest signal value among them is taken out. The clutch hydraulic pressure is controlled via the clutch hydraulic pressure control valve DEA, which is fed to the electro-pneumatic-hydraulic converter. In addition to the above-mentioned clutch hydraulic control valve, the hydraulic control system of the slipping clutch includes a clutch hydraulic pressure regulating valve 2c, a lubricating oil regulating valve 2 (1), and the details are omitted here. The figure is a characteristic curve diagram showing changes over time in each control value when the speed setting signal for carrying out the above control is suddenly increased.The diagram shows the clutch oil pressure p (KP/ cm), motor drive current [A], clutch oil temperature T (℃), clutch output shaft rotation speed N (
The respective change characteristics of P, 1.rpm) are P, 1. They are shown as T, N, U is the acceleration range, ■ is the constant speed range, and V1eV
2 is the constant speed control range, U,, U, is the current control range where the current value has reached its limit value, and U is the temperature control range where the temperature value has reached its limit value, respectively. It shows. Further, the constant speed range V corresponds to the speed control range. Next, the above operation will be explained with reference to FIG.

When the rotation of the induction motor 1 is applied to the load 3 through the variable speed slipping clutch, the output shaft to the load 3 lights up.In the first stage, when a speed setting signal for acceleration is applied to the speed setting device 6a, The current rotational speed of /c is detected by the rotational speed detector /d.

It is compared with the speed detection signal given through the F/V conversion circuit/f, and the difference is taken out as a proportional output signal and sent to the minimum value selector 7. However, generally in the initial stage of acceleration, The lubricating oil temperature after cooling the clutch is much lower than the limit temperature set value, and the motor drive current value is also much lower than the limit current set value, so current comparator Hiroshi and temperature comparator 3 output electrical signals that are close to the maximum. Therefore, the minimum value selector 7 takes out the signal output from the speed comparator 6, which has a small number, and sends it to the electric/oil converter 9 via the V/I output circuit and converts it into hydraulic pressure to operate the clutch. control hydraulic pressure,
Accelerate the clutch toward the set speed to adjust the rotational speed of the clutch output shaft to the set speed. Next, in the first stage where the load is accelerated to a certain extent, a large current begins to flow through the induction motor 1, and at the same time, the temperature of the lubricating oil after cooling the clutch begins to rise. As the W flow value increases and approaches the set limit value, the output signal of current comparator q begins to decrease, and similarly, the lubricating oil temperature after clutch cooling increases and approaches the set limit value. and the output signal of the temperature comparator 3 starts to decrease.As mentioned above, the minimum value selector 7 always compares the output signals of the temperature comparator j and the speed comparator 6 to the current comparator, and selects the lowest signal as the current comparator. -Tomari Converter Ri or Kame-
The clutch operating oil pressure is automatically controlled by sending it to the air-to-oil converter, so no matter how the speed setting signal is set to 9, the current value and the lubricant line temperature after the clutch has cooled will still exceed the limit value. You can prevent it from exceeding. Furthermore, as long as the output signal of the speed comparator base does not decrease compared to the output signals of the current comparator and temperature comparator 3, the maximum output corresponding to that output signal can continue to be sent to the electric-oil receiver, so that the electric motor 1. Driving power should always be maximized and used effectively in a safe manner.

The above control described acceleration under constant speed rotation with different slip states at the beginning and end, but when the clutch accelerates from a stopped state to a constant speed slip state or to a directly connected state, or from a slip state to a directly connected state. In the case of doing so, it is possible to control in a similar manner and is included in the present invention.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a control circuit according to an embodiment of the present invention, and FIGS. 1 and 3 are characteristic curve diagrams showing cases in which changes over time of each control value are not controlled and cases in which they are controlled. In the figure, l is the induction motor, c is the slipping clutch, 3 is the load, da is the current comparator, 3 is the temperature comparator, 6 is the speed comparator, 7 is the minimum value selector, and za is the V/I output circuit. De is an electric/oil converter, /a is a current detector, :1a is a temperature detector, /d is a rotation speed detector, ua, &a, and 6a are signal setting devices. Patent applicant: Niigata Compa → - Co., Ltd. Figure 1 Figure 2 j (sec) Figure 3 j (sec)

Claims (1)

[Claims] l When acceleration is performed by applying the rotation of the electric motor to a load via a slipping clutch, a means is provided to detect the input current of the electric motor, the lubricating oil temperature after the clutch has been cooled, and the rotational speed of the clutch output shaft, respectively! The converted electrical signals leaked from each detection means are subjected to comparison calculations via means for comparing with respective setting signals, and the safest and most effective signal value is calculated based on these comparison power signals, and this calculation output is By further applying a signal to an electro-pneumatic converter or an electro-hydraulic converter to control the working oil pressure of the clutch, the electric current value of the electric motor and the lubricating oil temperature after cooling the clutch can be controlled to exceed the limit values. An acceleration control device for a variable speed slipping clutch, characterized in that it accelerates a load Z to a set speed as quickly as possible.