JPH02303301A - Motor car - Google Patents

Abstract

PURPOSE:To shorten brake distance and to improve durability of mechanical brake means by applying generative brake while interlocking with the operation of brake lever. CONSTITUTION:Upon operation of a brake lever, a brake switch SW2 is turned OFF to switch the contact RS1 of a relay RM1 to the side of a generative brake resistor R31. At the same time, a transistor T6 is turned OFF to interrupt power supply to the field winding M1 of a motor M and to release the contact RS2 of a relay RN2. Consequently, a generative brake circuit is formed with the armature M2 of the motor M, the relay contact RS1, and resistors R31, R32. Then a voltage for turning a transistor T6 OFF through a comparator COP3 is produced and the field winding M1 conducts again, and thereby current flows through the generative brake circuit, thus applying generative brake force through the resistors R31, R32.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Industrial Application Field The present invention relates to electric vehicles such as golf carts, electric wheelchairs, and electric cars.

(b) Conventional technology Previously, as this type of electric vehicle, patent application No. 63-203356
I suggested the issue. Since this electric vehicle is stopped only by mechanical braking, it has drawbacks such as a long braking distance and poor durability of the mechanical braking means.

(c) Problems to be Solved by the Invention The present invention was made in view of the above-mentioned drawbacks, and an object thereof is to provide an electric vehicle that can shorten the braking distance and improve the durability of the mechanical braking means.

(d) Means for Solving the Problems A switch means for stopping energization to the field winding of the motor in conjunction with a brake lever, and a switch means for closing a dynamic braking circuit that returns to the armature of the motor through a resistive load;
The present invention is characterized by further comprising a control means for detecting power generation of the dynamic braking circuit and energizing the field winding.

(e) Operation When the brake lever is operated, the switch means stops energizing the field winding of the motor in conjunction with the brake lever, and the switch means closes the dynamic braking circuit. Then,
The control means detects the power generation of the dynamic braking circuit, energizes the field winding, applies dynamic braking to the electric vehicle together with the mechanical braking means, and stops the electric vehicle.

(F) Embodiment The present invention will be explained using the illustrated golf cart 1 as a specific example.

1 is a circuit diagram of the golf cart 1, FIG. 2 is a perspective view of the golf cart 1, FIG. 3 is a sectional view of the operation box 2 of the golf cart 1, and FIG. 4 is a plan view of the operation box 2. be.

The golf cart 1 has a body frame 4 formed by combining and connecting pipe bodies, and a car Va drive DC commutator motor M, a storage battery B, a control circuit, etc. are attached to the lower part of the body frame 4, and each part is covered with a body cover 5. It is covered to protect it from water.

A drive wheel 6 is pivotally supported at the rear lower part of the main body frame 4, and the drive wheel 6 is driven by a motor M. A steering wheel 7 is supported at the front lower part of the main body frame 4. A golf bag mounting portion 8 is formed at the front lower part of the main body frame 4, and a golf bag support 9 is formed at the front upper part of the main body frame 4.The rear upper part of the main body frame 4 is a handle 10. An operation box body 2 is attached to the center of the machine. A brake lever 11 is formed on the handle 10. By pulling the brake lever 11 to the handle 10, a mechanical brake (not shown) is operated via the wire 12 to prevent the drive wheel 6 from rotating. The brake switch SW2 is also operated in conjunction with the operation of the brake lever 11, and when the brake lever 11 is pulled to the handlebar 1° to apply the brake, the brake switch SW2 is released.

The operation box body 2 includes an upper wall 13 molded from synthetic resin, and a cylindrical portion 14 formed from a sheet metal whose upper opening is closed by the upper wall 13. A hanging rib 15 is formed around the upper wall 13,
The hanging rib 15 covers the outer side of the upper edge of the cylindrical portion 14 and the screw 16
The two are combined. At the center of the upper wall 13, a shaft support 19 is formed by a cylindrical portion 17, 18 that continuously projects from the outer and inner surfaces of the upper wall 13. The operating shaft 2o is inserted through and supported by the shaft support 19. A rotary operating knob 21 is fixed to the upper end of the operating shaft 2o that protrudes from the cylindrical portion 17, and an operating body 22 is fixed to the lower end that protrudes from the cylindrical portion 18. Upper wall 1
3. A circuit board 23 is mounted above the lower end of the recess 18 on the inner surface, so-called the lower end of the shaft support 19. 0. The circuit board 23 is equipped with the main switch SW and brake switch SW shown in FIG.
All parts except 2 are installed and wired. main switch s
W is attached to the cylindrical portion 14 so that its operating portion is exposed. So, S r, S2. S3. S4. S
S, Sb, S7, and S8 are reed switches, which constitute a setting section for stopping and controlling the speed of the motor M, and are magnetic sensing elements that are turned on when a magnetic body approaches or separates. Reed switch So, S
2,...S8 has resistors R1, R2, and R3 connected in series.
゜R4,Rs,R6,R? , R11 are connected.

The operating body 22 is an operating plate 24 formed of a synthetic resin disc body.
and a magnetic body 25 attached to the upper surface of the outer periphery of the operation plate 24. A plurality of recesses 27 are formed on the upper surface of the operation plate 24, into which engagement bodies 26 that hold the operation plate 24 in an appropriate rotational position are engaged. The engaging body 26 is biased by a spring 28 and
There are 0 pieces stored in 2 storage areas of 3, and the recess 27 has 9 pieces.
Formed individually. The position where the operating plate 24 is held by the engaging body 26 is that the magnetic body 25 is the reed switch SO+ S1+...S
This is the position corresponding to @. Further, a pointer portion 30 is formed on the rotary operation knob 21, and a display board 31 is attached to the top surface of the earthen wall 13, indicating each holding position of the operation plate 24 and indicating the set center of gravity using the pointer portion 30. .

As shown in FIG. 4, the display board 31 is provided with displays indicating nine set positions and text indicating the status of the motor M.

In the display plate 31, the cylindrical portion 17 has an insertion hole in the center, and the rotary operation knob 21 covers the cylindrical portion 17.

The golf cart 1 is used outdoors, and when it is used in the rain, the operation box body 2 gets wet with water, but the water falling on the upper wall 13 flows down without entering into the N part 14 from the surroundings. Since the operating shaft 20 is pivotally supported by the cylindrical portion 17, water cannot rise up the cylindrical portion 17, and water is prevented from entering from the shaft support 19. When water rises in the cylindrical portion 17 due to the wind and enters into the cylindrical portion 14 through the gap between the operating shaft 20 and the shaft support 19, the infiltrated water flows over the upper surface of the operating body 22 and flows downward. As a result, water that has entered does not reach the circuit board 23 located above the operating body 22, and electrical insulation is maintained well.

Note that no electrical parts are attached to the sheath section 14 located below the operating body 22, and the main switch SW1 is naturally attached to the lower part of the box section 14 that is attached to the upper part of the sheath section 14. A drainage hole is formed to drain water.

A current limiting resistor R32 and an armature current detecting resistor R33 are connected in series to the armature M2.
12 is short-circuited by a relay contact RS2 which is turned on by a relay coil RM2 of a starting compensation relay. Armature M
2 and storage battery B is the relay coil R of the main relay.
It is connected via a relay contact RS, which is turned on at M. A diode D is connected in parallel to the field winding M1 of the motor M.
A current control transistor T6 is connected in series to the field winding and tJIMI. A parallel circuit of diodes Db, Dr, and Da is connected to the base terminal of the transistor T6. Diode D7 is connected to the output of comparator cop, and diode D8 is connected to the output of comparator C0P2. Diode D6 is connected via diode D to the collector terminal of transistor T4, which controls relay coil FLM2. A delay circuit consisting of resistors Rts and Rt7 and a capacitor C1 is connected to the base terminal of the transistor T4. The delay circuit is connected to the emitter terminal of the stall control transistor T. The main relay coil RM is connected to the base terminal of the transistor T.
+The collector terminal of the control transistor T2 is connected. Resistors R,,,R are connected to the base terminal of the transistor T2.
1.

R1, , R2, and resistance R2...R of the speed variable operation section 3
11 is connected. Resistors RI4 and R2 are constant voltage circuit A
3 and the storage battery B via the main SW1, and the connection between the resistors R14 and R21 is connected to the + of the comparator COP s.
Connected to the input terminal. The positive input voltage of the comparator cop is changed by the operation of the speed variable operation section 3. Comparator CO
The + input terminal of P2 is connected between armature M2 and resistor R33, and the voltage of resistor R33 is input. Comparator C0P
The output from the triangular wave generator A2 is divided by resistors R22 and R2 and applied to the input voltages I and cop. One input terminal of the comparator cop is set to be larger than one input terminal of the comparator COP x.

The abnormality detection part AI has two pieces EXCt, tJSIVE OR
A circuit is connected to form the output terminal e of the alarm generator S.
It is connected to the base terminal of a transistor T, which controls P. The inputs are resistors R,,Rt. ,Rt,,R,□.

By connecting to R13, input terminal a is connected to brake switch SW2, and input terminal a is connected to relay coil RM.
+ and the transistor T2, the input terminal d is connected to the collector terminal of the transistor T, and the base terminal of the transistor T is connected to the movable contact of the main relay RS through a resistor R2°.

The base terminal of the transistor T5 is connected to the collector terminal of the transistor T7, and the base terminal of the transistor T7 is connected to the +input terminal of the comparator COP3. The output from the constant voltage circuit A3 is divided by resistors R2 and R3 and applied to one input terminal of the comparator C0P3, and the output terminal of the comparator cop is connected to the base terminal of the transistor T6 via the diode D11. The zero-power braking resistor R31 connected to the main relay RS and the relay contact R
52 movable contacts.

Next, the operation of the motor M will be explained.

Switches SW, SW2 and relay contact RS shown in Figure 1
I, RS, Reed switch So, S+...S,
In this state, the main switch SW of the golf cart 1 is turned off, the brake is applied and the wheels are fixed, the speed variable operation section 3 is turned off, and the reed switch S is turned off. is being inserted.

Next, when the main switch SW and brake switch SW2 are turned on, the reed switch S is turned on. is turned on, transistor T2 maintains non-conduction, and relay contact RS
Both S and RSR will maintain their current status.

When the rotary operation knob 21 is rotated by one scale, the magnetic body 25 is shifted from the reed switch S0 to the position of the reed switch S, and the reed switch S0 is turned off. Then, the transistor T2 becomes conductive, energizing the relay coil RM and connecting the relay contact RS to the armature M2. At this time, the transistor T4 is non-conductive for a charging time of the capacitor C8, and then the relay coil RM2 is energized to close the relay contact RS2. At this time, the input voltage of the comparator COP is higher than the input terminal of the comparator COP, and the diode D7 is at a high level, the transistor T6 is always conductive (duty 100%), and the motor M rotates at the lowest speed. However, until the transistor T4 becomes conductive, the motor M is started by the series circuit of resistors R32 and R33, and the starting torque is reduced, so that the motor starts slowly and can be started reliably even on an uphill slope.

Also, until the transistor T4 becomes conductive, the diode D
6 becomes high level, and the diode D7. Since the duty of the transistor T6 is 100% regardless of the level of Dll, when the brake is applied and the reed switch S1...S6 is selected to release the brake, the transistor T6 is always turned on until the transistor T4 becomes conductive. Since it is conductive with a duty of 100% during this time, it is possible to perform a start with good starting performance and no sudden start.

By sequentially switching from reed switch S1 to 88, the input voltage becomes smaller, the high level time of the output of diode D7 becomes shorter little by little compared to the state in which reed switch S1 is turned on, and the motor M gradually becomes faster. be driven. Further, when the reed switch S8 is turned on, the high level time of the output of the diode D7 is shortened, and the motor M is operated at the maximum speed. However, the faster the motor M rotates, the smaller the torque becomes.

To explain the situation when traveling uphill, going uphill requires a large torque, but if the high speed is set, the torque is small and the load on the motor M increases, resulting in a decrease in rotational speed. When the rotational speed decreases, the current in armature M2 increases, and the input voltage of comparator C0P2 increases, causing an overlap with one input terminal, generating an output from diode D8, prolonging the high level time, and increasing the voltage of the transistor. At T6, the duty increases, the rotational speed of the motor M changes to the lower speed side, the torque increases, and the vehicle can run uphill smoothly.

Next, the case of performing a brake operation will be explained.

When the brake lever 11 is operated, the brake switch S
When W2 is 0FFL, the relay contact RS of the main relay is switched to the fixed contact on the side of the dynamic braking resistor Rit, and the transistor T6 is turned off to stop energization of the field winding M of the motor M, and at the same time, the start compensation relay is activated. relay contact RS,
opens.

In this state, armature M2 of motor M, relay contact RS
,, A dynamic braking circuit is formed by the resistors R31 and R32, and a voltage is generated in this dynamic braking circuit.

Input this voltage to the ten input terminal of comparator COP3, and -
Comparing the output from the constant voltage circuit A input from the input terminal with the voltage divided by the resistors R23 and R2°, if the input voltage is greater than the one input terminal, the comparator COP3 becomes an H output, and the transistor T6 It is always conductive to the field winding M of the motor M. When a field current flows through the motor M, a current flows through the dynamic braking circuit, and a dynamic braking force is applied by the resistors R3 and R12.

The resistors R2 and Rlo are connected to the output voltage of the constant voltage circuit A3 divided by the resistors R29 and R1°, that is, one input terminal of the comparator cop when the golf cart 1 is lightly pushed by hand. The voltage generated in the dynamic braking circuit, that is, the comparator C
The value is set to be slightly larger than the input voltage of 0P3. Therefore, even if the brake is operated while the golf cart 1 is running at a low speed, the same field current flows as when the golf cart 1 is running at a high speed.

Furthermore, when the golf cart 1 is moved by hand from a stopped state, the input voltage of the comparator cop is lower than the input terminal of the input terminal, the output of the comparator cop becomes L, and the transistor T6 remains OFF. Therefore, field current does not flow. Therefore, no dynamic braking force is generated and it can be easily moved by hand.

In the abnormality detection section A1, when the golf cart 1 is running, the input terminals A and D are at a low level, and the input terminal a is at a high level, so the output field C is at a high level and the transistor T is turned on.

is OFF and the generator SP does not sound. Main switch SW
+ or brake switch S W 2 is turned OFF,
Since input terminals a and b are at low level and input terminal d is at high level, output terminal e is at high level.
Generator SP does not sound. When main switch SWI and brake switch SW2 are ON, turn on reed switch So.
Then, input terminals a', b, and d become high level,
Output terminal e becomes high level, and generator SP does not sound. Therefore, when the golf cart 1 is in a normal state, the generator SP does not sound.

Furthermore, even if the relay contact RS + is welded while connected to the armature M2, the speed variable operation section 3 will set the reed switch S0, that is, a state other than "off", and the main switch SW + will also be connected to the brake switch. In a running state where SW2 is not operated, the generator SP does not sound because it operates in the same way as in a normal state.

Next, when relay contact R5 is welded while connected to armature M2, main switch SW.

When the reed switch S0 is turned OFF, the brake lever 11 is operated to turn the brake switch SW2 OFF, or the rotary operation knob 21 is operated to turn the reed switch S0 ON, the generator SP sounds. That is, when each of the above-mentioned operations is performed, the abnormality detection section A.

The input changes at input terminals a and b are the same as in normal operation, and the main switch SW or brake switch SW2 is turned OFF.
When the reed switch So is turned on, it becomes a high level, and the intermediate output terminal C becomes a low level. On the other hand, since the input terminal d is always at a low level due to welding of the relay contact RS1, the output terminal e is at a low level, the transistor T is turned on, and the generator SP sounds.

If any or more of the above three operations is performed with the contacts welded, the field winding MI is not energized because the transistor T6 is turned OFF, and the armature M2 and the resistors R32, R,... The motor M is energized, and the motor M is unable to run with zero torque and stops. If this state continues, the armature M2 and the resistors R3, , R, will generate abnormal heat and there is a risk of ignition.

In particular, in the case of Golf Cart 1, the resistor R32 that intervenes in order to obtain sufficient starting torque at startup and to start slowly without suddenly starting is a nichrome resistor because of ease of assembly, cost, and design considerations. It will become red hot, and only when this condition occurs will the generator S be turned off.
P sounds to notify you of an abnormality.

Furthermore, when the brake is operated, the transistor T is turned on due to the generated braking current, even though the contacts are not welded.
L, there is a risk of a malfunction in which the generator SP sounds, but the dynamic braking current causes the transistor T7 to turn ONL,
The output of resistor R2゜ is connected to transistor T? absorbs, so
When the transistor T5 is OFF, malfunction of the generator SP can be prevented.

(G) Effects of the Invention As described above, according to the present invention, dynamic braking can be applied in conjunction with brake lever operation, and braking can be performed by mechanical braking and dynamic braking, so the braking distance can be shortened. At the same time, the durability of the mechanical braking means can be improved.

[Brief explanation of drawings]

The drawings all show an embodiment in which the present invention is applied to a golf cart, with Figure 1 being an electric circuit diagram, Figure 2 being a perspective view, and Figure 3 being a perspective view.
The figure is a sectional view of the operation box body, and FIG. 4 is a plan view thereof. M...Motor, M...Field winding, M2...Armature, SW2...Brake switch, RS,...Relay contact of main relay, COP3...Comparator.

Claims (1)

[Claims] (1) A switch means for stopping energization to the field winding of the motor in conjunction with the brake lever, a switch means for closing a dynamic braking circuit that returns to the armature of the motor through a resistive load, and a switch means for stopping power generation in the dynamic braking circuit. An electric vehicle characterized by comprising: a control means for detecting and energizing the field winding.