JPH0799883B2 - Brake device for electric vehicles - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a braking device for an electric vehicle that uses a regenerative brake (electric brake) and an air brake together, and particularly, facilitates switching between the regenerative brake and the air brake. The present invention relates to a braking device for an electric vehicle, which has improved riding comfort and handleability of the electric vehicle.

[Prior Art] FIG. 3 is a block diagram showing a conventional electric vehicle brake device described in, for example, Japanese Patent Publication No. 63-12831.

In the figure, (1) is a brake command device that outputs a braking force command A, (2) is a motor control circuit that outputs a regenerative braking force signal B based on the braking force command A, and (3) is a regenerative braking force signal B. Is a motor that generates a regenerative braking force C in accordance with the above.

(4) is a comparator that outputs the air braking force command D by taking the difference between the braking force command A and the regenerative braking force signal B,
(5) is an electro-pneumatic conversion valve that converts the air braking force command D from an electric signal into air pressure E, and (6) is an air brake device that is driven by the air pressure E to generate an air braking force F.

Next, referring to the timing chart of FIG. 4,
The operation of the conventional electric vehicle braking device shown in FIG. 3 will be described.

Normally, during braking, the regenerative brake mainly acts, and the air brake makes up for the shortage of the regenerative brake, but it takes time until the regenerative brake circuit is formed. First, the air brake operates.

Therefore, when the brake force command A is output from the brake command device (1), first, the air pressure E rises according to the air brake force command D, and the air brake force F gradually increases.

Subsequently, when the regenerative braking circuit is formed and the regenerative braking force C rises, the air braking force command D is changed by the comparator (4) to the braking force command A and the regenerative braking force signal B.
The value becomes a value corresponding to the difference (corresponding to the regenerative braking force C), and the value of the air pressure E decreases as the regenerative braking force C increases.

Further, at the final speed of the brake, the rotation speed of the electric motor (3) decreases, so that the regenerative brake naturally expires and the regenerative braking force C gradually decreases. Therefore, the air pressure E input to the air brake device (6) rises as the regenerative braking force C decreases and increases the air braking force F.

Thus, by switching between the air brake and the regenerative brake when the regenerative brake rises and expires, the deceleration (C + F) corresponding to the sum of the regenerative braking force C and the air braking force F (total braking force) is ,
It is controlled to a value that substantially matches the braking force command A.

However, since the response of the air brake is slower than that of the regenerative brake, the following deceleration (C + F) fluctuation phenomenon occurs.

That is, when switching from the air brake to the regenerative brake when the brake is activated, the deceleration (C + F) becomes excessive X due to the delay in the response of the air pressure E, and when switching from the regenerative brake to the air brake at the end of braking. Is
The deceleration (C
+ F) becomes insufficient Y.

[Problems to be Solved by the Invention] As described above, in the conventional electric vehicle braking device, the regenerative braking force signal B corresponding to the regenerative braking force C is directly input to the comparator (4) and the air braking force command D is input. Since the deceleration (C + F) corresponding to the total braking force fluctuates due to the excessive phenomenon X and the insufficient phenomenon Y, the riding comfort of the electric vehicle becomes poor, and the handling of the brake by the driver becomes poor. There is a problem that inconvenience occurs due to excessive braking.

The present invention has been made to solve the above problems, and smoothes the change in deceleration at the time of switching between the regenerative brake and the air brake to improve the riding comfort and the handleability of the brake. An object of the present invention is to obtain a brake device for an electric vehicle that prevents inconvenience.

[Means for Solving the Problems] A braking device for an electric vehicle according to the present invention includes a motor for driving an electric vehicle, an electric motor control circuit for controlling the electric motor, a difference between a braking force command and a regenerative braking force signal for the electric motor. A subtractor that generates an air braking force command equivalent to
An electro-pneumatic conversion valve that converts an air brake force command into air pressure and an air brake device that generates an air brake force based on the air pressure are provided, and the motor control circuit detects the state of the regenerative brake for the motor. A braking device for an electric vehicle that includes a detection system and outputs a regenerative braking force signal, a circuit formation signal indicating that the regenerative brake has formed a circuit, and an invalidation detection signal indicating that the regenerative brake has expired, based on the braking force command. And the one-shot pulse generator that outputs the one-shot signal in response to the circuit formation signal and the one-shot signal and the regenerative braking force signal are taken higher than the one-shot signal and the one-shot signal is superimposed on the regenerative braking force signal. High-priority circuit that outputs a high-level signal and step-down that outputs a step-down signal in response to a revocation detection signal A loss generator and another subtractor that generates a corrected regenerative braking force signal by subtracting the step-down signal from the high level signal are provided, and the subtractor is based on the difference between the braking force command and the corrected regenerative braking force signal. The air brake force command is generated.

[Operation] In the present invention, when the regenerative brake rises, the one-shot signal accelerates the drop response of the air pressure (air brake), and when the regenerative brake expires, the step-down signal is subtracted to increase the rise response of the air pressure. The response delay of the air brake at the time of switching between the speed increase, the regenerative brake and the air brake is corrected to smooth the change in deceleration (total braking force).

[Embodiment] An embodiment of the present invention will be described below with reference to the drawings. First
FIG. 1 is a block diagram showing an embodiment of the present invention,
(1), (3) to (6) and A to C are the same as described above. Further, (2A), B ″, D ′, E ′ and F ′ respectively correspond to the motor control circuit (2), the regenerative braking force signal B, the air braking force command D, the air pressure E and the air braking force F. ing.

The electric motor control circuit (2A) includes a regenerative brake detection system that detects the state of the regenerative brake for the electric motor (3). Based on the braking force command A, a circuit for regenerative braking is provided in addition to the regenerative braking force signal B. A circuit formation signal G indicating that the regenerative brake has expired and an invalidation detection signal H indicating that the regenerative brake has expired are output.

(10) is a one-shot pulse generator that outputs a pulsed one-shot signal J in response to a circuit formation signal G, (1
1) is a high-level priority circuit that takes the high level of the one-shot signal J and the regenerative braking force signal B and outputs a high-level signal B ′ superposed with the one-shot signal J. (12) is the invalidation detection signal H
A step-down pulse generator that outputs a pulse-like step-down signal K in response to the above, and (13) another subtraction that subtracts the step-down signal K from the high-level signal B ′ to generate a corrected regenerative braking force signal B ″. (Hereinafter simply referred to as a subtractor).

Next, referring to the timing chart of FIG.
The operation of the embodiment of the present invention shown in FIG. 1 will be described.

First, when the air brake is switched to the regenerative brake when the brake is started, the motor control circuit (2A) outputs the regenerative brake circuit forming signal G, which causes the one-shot pulse generator (10) to generate the one-shot signal J. Is output.

Since the high-order priority circuit (11) takes the high level of the regenerative braking force signal B corresponding to the regenerative braking force C and the one-shot signal J, the one-shot signal J is sent to the subtractor (13) as the high-level signal B '. Is entered. At this time, the step-down signal K is off because the revocation detection signal H is not output.

Therefore, at the rising of the regenerative brake, the corrected regenerative braking force signal B ″ is increased by the one-shot signal J, so that the air braking force command D ′ output from the comparator (4) is suppressed and the air braking force F ′ is reduced. As a result, the air brake can be switched to the regenerative brake without the deceleration (C + F ′) corresponding to the total braking force becoming excessive.

On the other hand, when the regenerative brake is ineffective at the final speed of the brake, the motor control circuit (2A) outputs the ineffective detection signal H, which causes the step-down pulse generator (12).
Outputs a step-down signal K.

At this time, the one-shot signal J is not output, and the high priority circuit (11) inputs the regenerative braking force signal B corresponding to the regenerative braking force C to the subtractor (13) as the high level signal B '. There is.

Therefore, the subtractor (13) outputs a signal obtained by subtracting the step-down signal K from the regenerative braking force signal B as the corrected regenerative braking force signal B ″.

As a result, the corrected regenerative braking force signal B ″ is narrowed down by the step-down signal K, the air braking force command D ′ output from the comparator (4) increases, and the air braking force F ′ rapidly rises. Speed (C + F ')
Switch from regenerative braking to pneumatic braking without running out of air.

As a result, as shown in FIG. 2, it is possible to obtain a deceleration pattern having a waveform that matches the braking force command A.

In the above embodiment, the case where the number of the air brake device (6) is one has been described as an example, but the same effect can be obtained even when applied to the case of a so-called delayed brake device in which the second air brake device is combined. Needless to say.

As described above, according to the present invention, the electric motor for driving the electric vehicle, the electric motor control circuit for controlling the electric motor, and the air brake corresponding to the difference between the braking force command and the regenerative braking force signal for the electric motor. The electric motor control circuit includes a subtractor that generates a force command, an electropneumatic conversion valve that converts the air brake force command into air pressure, and an air brake device that generates an air braking force based on the air pressure. Includes a regenerative brake detection system that detects the state of the regenerative brake, and based on the brake force command, a regenerative brake force signal, a circuit formation signal indicating that the regenerative brake has been circuit-formed, and an invalidation detection indicating that the regenerative brake has expired. A braking device for an electric vehicle that outputs a signal, which generates a one-shot pulse that outputs a one-shot signal in response to a circuit formation signal And a high-level priority circuit that outputs a high-level signal in which the one-shot signal is superimposed on the regenerative braking force signal by taking the high level of the one-shot signal and the regenerative braking force signal, and a step-down signal in response to the revocation detection signal. A step-down pulse generator that outputs and another subtractor that subtracts the step-down signal from the high-level signal to generate a corrected regenerative braking force signal are provided. An air brake force command is generated based on the difference, and the one-shot signal accelerates the air pressure drop response when the regenerative brake rises, and the step down signal accelerates the air pressure rise response when the regenerative brake expires. Therefore, the response delay of the air brake at the time of switching between the regenerative brake and the air brake is corrected and decelerated. Change is smooth, well and good brake handle properties are ride comfort, the effect of electric vehicle braking device is obtained which can prevent a disadvantage due to an excessive braking or the like.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a timing chart diagram for explaining the operation of FIG. 1, and FIG. 3 is a block diagram showing a conventional electric vehicle brake device. FIG. 4 is a timing chart for explaining the operation of FIG. (2A) …… motor control circuit, (3) …… motor, (5)
Electro-pneumatic conversion valve (6) Air brake device (10) One-shot pulse generator (11) High-priority circuit (12) Step-down pulse generator (13) Another subtraction Device, A ... Brake force command B ... Regenerative brake force signal B '... High level signal B "... Corrected regenerative brake force signal D' ... Air brake force command E '... Air pressure, F' ... Air Braking force G ... Circuit formation signal, H ... Invalidation detection signal J ... One shot signal K ... Step down signal In the drawings, the same reference numerals indicate the same or corresponding portions.

Claims (1)

[Claims] 1. An electric motor (3) for driving an electric vehicle, an electric motor control circuit (2A) for controlling the electric motor (3), a braking force command (A) and a regenerative braking force signal for the electric motor (3) ( B), a subtractor (4) for generating an air braking force command (D '), and an electropneumatic conversion valve (4) for converting the air braking force command (D') into air pressure (E '). 5) and an air brake device (6) that generates an air braking force (F ') based on the air pressure (E'), and the electric motor control circuit (2A) regenerates the electric motor (3). A regenerative brake detection system for detecting the state of the brake is included, and the regenerative brake force signal (B) and a circuit formation signal (G) indicating that the regenerative brake has been formed into a circuit based on the brake force command (A). And the regenerative brake has expired And a one-shot pulse generator (10) for outputting a one-shot signal (J) in response to the circuit formation signal (G), which is a brake device for an electric vehicle that outputs a revocation detection signal (H) indicating that , The one-shot signal (J) and the regenerative braking force signal (B) are taken high, and a high-order signal (B ′) in which the one-shot signal (J) is superimposed on the regenerative braking force signal (B) is output. A high priority circuit (11) for outputting and a step down pulse generator (12) for outputting a step down signal (K) in response to the invalidation detection signal (H).
And another subtractor (13) for subtracting the step-down signal (K) from the high-order signal (B ′) to generate a corrected regenerative braking force signal (B ″), the subtractor (4) Is an electric vehicle brake device, wherein the air brake force command (D ′) is generated based on a difference between a brake force command (A) and the corrected regenerative brake force signal (B ″).