JPH01114384A - Controller for vacuum pump motor - Google Patents

Abstract

PURPOSE:To reduce an impact at the time of starting the fitted-on connected section of a motor and a vacuum pump, by increasing motor current slowly after the operation of an operating switch. CONSTITUTION:When an operating switch 14 is turned ON, then charging capacitors 15, 16, 17 is started. In this case, from an operational amplifier 18, signal according to a difference between the current detection signal of a motor 12 and the voltage of a connecting point f is fed to the base of a transistor Tr 1. Then, current fed to the motor 12 is slowly increased. By the rotation of the output shaft 12a of the motor 12, a clearance delta between the output shaft 12a and the rotary shaft 11a of a pump 11 is avoided, and a rugged section is butted to. When the voltage of the capacitor 17 comes to a specified value and a transistor Tr 2 is turned ON, then the output voltage of the operational amplifier 18 is heightened, and the transistor Tr 1 is set in a saturated state, and the whole voltage of a battery 13 is applied to the motor 12.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a vacuum pump motor control device used in a pneumatic brake booster of a vehicle without a negative pressure system, such as an electric vehicle.

(Prior art) In conventional pneumatic V1 dynamic boosters, pressure is obtained by driving a vacuum pump using the rotation of the engine, but in cars without a negative pressure system, such as electric cars, the motor is rotated. Generally, pressure is obtained by driving. In this vacuum pump motor, the vacuum pump and the motor are integrated, so the coupling structure between the two should be small and simple. For example, as shown in Fig. 2, it is formed at the end of the output shaft 1 of the motor. A vacuum pump in which the recessed portion 2 and the protrusion 4 formed at the end of the rotating shaft 3 of the vacuum pump are fitted and connected is used.

(Problem to be solved by the invention) However, the fitting connection between the motor and the vacuum pump (
A clearance (gap) δ is required for manufacturing (uneven parts), and as a result, when operating the operation switch (when starting the motor)
Since these uneven portions collide with each other, repeated use causes wear, significantly shortening the life of the fitting connection portion.

(Object of the Invention) It is an object of the present invention to provide a vacuum pump motor control device that solves the above-mentioned problems and can reduce the impact at the time of startup of the fitting connection between the motor and the vacuum pump, thereby extending the life of the motor.

(Means for Solving the Problems) In order to achieve the above-mentioned object, the present invention includes a motor having an output shaft fitted and connected to a rotating shaft of a vacuum pump connected to a vacuum tank, and a motor connected to a power source to connect the motor to a power source. A vacuum pump motor control device includes a transistor connected in series with a transistor, and transistor control means for controlling a signal to a signal input terminal of the transistor so as to gradually increase the motor current after operation of an operation switch. That is.

(Function) After the operation switch is operated, the transistor control means sends a signal to the signal input terminal of the transistor to gradually increase the motor current. As a result, when the motor is started, the current flowing through the motor is small, and both shafts of the vacuum pump and the motor, which are fitted and connected, come into contact with each other with a weak rotational torque.

(Example) An example embodying the present invention will be described below with reference to the drawings.

As shown in FIG. 1, a vacuum bomb 11 for generating negative pressure for the brake booster is connected to a vacuum tank (not shown), and a pump motor (DC motor) 12 is connected to a vacuum tank (not shown).
It is driven by. As shown in FIG. 2, the vacuum pump 11 and the pump motor 12 are connected to each other by fitting their rotating shafts 11a and 12a to each other. That is,
The recess 2 and the hole 1 formed in the output shaft 12a of the motor 12
- The convex portion 4 formed on the rotating shaft 11a of the pump 11 is fitted with a clearance (gap) δ, and the rotation of the output shaft 12a of the motor 12 is controlled by the rotating shaft 11a of the pump 11.
transmitted to.

The motor 12, a first transistor Trl, and a resistor r1 are connected in series between both terminals of a battery 13 serving as a power source. Further, an operation switch 14, a resistor r2, and a capacitor 15 are connected in series between both terminals of the battery 13. This switch 14 is a brake operation switch that closes in conjunction with a brake pedal (not shown), or a switch that detects negative pressure generated by the vacuum pump 11 and closes when the pressure falls below a predetermined pressure.

A connection point a between the resistor r2 and the capacitor 15 is connected to a base terminal as a signal input terminal of the first transistor Tr1 via a resistor r3. The connection point between the operation switch 14 and the resistor r2 is the battery 13.
A series circuit of a resistor r4 and a capacitor 16 and a series circuit of a resistor r5 and a capacitor 17 are connected in parallel between the negative terminal of the resistor r4 and the capacitor 16. Connection point C between resistor r4 and resistor r5 and connection point d between resistor r4 and capacitor 16
A second transistor Tr2 and a resistor r6 are connected in series between them. Further, a diode D1 in parallel with the resistor r5 is connected to a connection point e between the resistor r5 and the capacitor 17, and the base terminal of the second transistor Tr2 is also connected thereto. A resistor r7 in parallel with the capacitor 16 is connected to a connection point f between the resistor r4 and the capacitor 16.

The connection point σ between the first transistor Tr1 and the resistor r1
is connected to the inverting input terminal of the operational amplifier 18 as a transistor control means through a resistor r8, and the connection point between FLr8 and the inverting input terminal of the operational amplifier 18 is connected to the negative terminal of the battery 13 through a capacitor 19. It is connected to the.

The non-inverting input terminal of the operational amplifier 18 is connected to the connection point f, and the output terminal of the operational amplifier 18 is connected to the base terminal of the first transistor Tr1 via the diode D2.

Next, the operation of the vacuum pump motor control device configured as described above will be explained.

When the operation switch 14 is turned on (closed), the capacitor 1
5.16.17 are resistors r2. Charging is started via r4 and r5, and the non-inverting input terminal of the operational amplifier 18 detects the voltage at the connection point f, and the inverting input terminal detects the voltage of the current of the motor 12 by the resistor r1, and outputs the voltage to the capacitor 19. Smooth and detect. The operational amplifier 18 initially outputs a small current to the base terminal of the first transistor Tr1 in accordance with the voltage difference between the inverting input terminal and the non-inverting input terminal. Therefore, the first transistor Tr1 operates in an unsaturated state due to this base current, and flows a weak collector current. This collector current causes current to flow through the motor 12, and the motor 12 starts rotating.

Then, due to the charging operation of the capacitor 16, the operational amplifier 1
The voltage at the non-inverting input terminal of transistor T8 rises, and the voltage difference with the inverting input terminal gradually increases, and the operational amplifier 18 gradually increases current to the first transistor T in accordance with the increase in the potential difference.
Output to the base terminal of r1. As a result, the motor 12
The current is also applied so that the current gradually increases and the output torque increases. At this time, due to the rotation of the output shaft 12a of the motor 12, the output shaft 12a and the rotation shaft 11a of the pump 11 are connected to each other.
The clearance δ between the two ends disappears, and the uneven parts come into contact with each other.

Then, when the second transistor lower r2 in the integrating circuit composed of the resistor r5 and the capacitor 17 is turned on, the capacitor 16 is rapidly charged via the resistor r6. Therefore, the voltage at the non-inverting input terminal of the operational amplifier 18 increases, and the current output to the base terminal of the first transistor Tr1 also increases, causing the transistor Tr1 to become saturated (turned on), and the entire voltage of the battery 13 is applied to the motor 12. is applied and enters normal operating state.

After that, when the operation switch 14 is turned off, the capacitor 1
The first transistor Tri is turned on to drive the motor 12 during a period when the charges stored in the transistor 5 are discharged.

As described above, in this embodiment, by operating the transistor Tr1 in an unsaturated manner, when the operation switch 14 is turned on, the motor current (output torque) gradually increases over a short period of time (for example, several tens of m5), so that the motor 12 starts slowly. As a result, the concave and convex portions of the motor 12 and the pump 11 slowly come into contact (contact), and then the motor 12 rotates with full voltage applied, so when starting the motor 12 by applying full voltage as in the conventional case, There is no impact on the mating connection. Therefore, the concave portion and convex portion of the fitting connection portion between the motor 12 and the pump 11 may be machined with general dimensional accuracy. Further, the fitting connection part has the simplest structure of a combination of a concave part and a convex part, so that the vacuum pump 11 and the motor 12 can be made compact. Furthermore, it can be configured with the simplest recess and protrusion as a fitting connection method, and the above-mentioned dimensional clearance can be obtained without strictly controlling manufacturing conditions, and manufacturing costs can be significantly reduced.

Furthermore, the mating connection slowly comes into contact (contact) at startup.
Until this happens, the first transistor Tr1 is operated in unsaturated state, and after the fitting connection comes into contact, the transistor Tr1 is completely turned on (saturated), so the motor 12 is controlled intermittently in response to the operation switch 14. In this case, the increase in moisture level due to the unsaturated operation of the transistor Tr1 when starting the motor can be ignored.

Effects of the Invention As detailed above, according to the present invention, the excellent effect of reducing the impact at the time of startup of the fitting connection portion between the motor and the vacuum pump and extending the life of the motor is exhibited.

[Brief explanation of the drawing]

FIG. 1 is an electric circuit diagram of a vacuum pump motor control device embodying the present invention, and FIG. 2 is a diagram showing a state in which the rotating shaft of the vacuum pump and the output shaft of the motor are connected. 11 is a vacuum pump, 11a is a rotating shaft, 12 is a pump motor, 12a is an output shaft, 13 is a battery as a power source, 14 is an operation switch, and 18 is an operational amplifier as a transistor control means.

Claims (1)

[Scope of Claims] 1. A motor having an output shaft fitted and connected to a rotating shaft of a vacuum pump connected to a vacuum tank, a transistor connected in series with the motor to a power source, and an operation switch. A vacuum pump motor control device comprising transistor control means for controlling a signal to a signal input terminal of the transistor so as to gradually increase the motor current after operation.