JP4686964B2 - Connection structure of booster circuit to battery - Google Patents

Description

  The present invention relates to a connection structure of a booster circuit to a battery, and more particularly to a connection structure of a booster circuit of an electronic control device to a battery.

  Conventionally, an ECU 100 (electronic control unit) mounted on a vehicle is supplied with electric power from a battery B via a wiring 110 as shown in FIG. The ECU 100 is provided with a booster circuit 200, and a voltage boosted by the booster circuit 200 is applied to the motor M so as to drive and control the motor M.

  However, since the conventional booster circuit 200 is incorporated in the ECU 100 and connected from the battery B via the wiring 110, a large voltage is generated by the wiring resistance between the battery B and the booster circuit 200 and a large current flowing through the wiring. A drop (voltage drop) occurred, which hindered an increase in the output voltage of the booster circuit 200.

  The object of the present invention is to eliminate the wiring from the battery to the booster circuit, eliminate the voltage drop due to the wiring resistance and large current during the operation of the booster circuit, and as a result, greatly improve the output voltage rise width of the booster circuit An object of the present invention is to provide a connection structure of a booster circuit that can be connected to a battery.

In order to solve the above-mentioned problem, the invention according to claim 1 detachably attaches a connecting member to which one end of an electric wire is connected to a battery terminal of a battery. The connection terminal connected to the booster circuit for boosting the voltage is directly attached to the battery terminal .

  According to a second aspect of the present invention, in the first aspect, the booster circuit is housed in a housing different from the housing housing the electronic control device including a control unit that controls the actuator, and the connection terminal houses the booster circuit. And projecting from the housing to the outside and directly attached to the battery terminal.

According to a third aspect of the present invention, in the second aspect of the present invention, the contact surface of the connection terminal that comes into contact with the outer peripheral surface of the battery terminal when connected to the battery terminal is formed into a rough surface.
The invention of claim 4 is the contact surface according to claim 3 , wherein the battery terminal is formed in a cylindrical shape, and the connection terminal is recessed in a circular arc shape along the outer peripheral surface of the battery terminal. It is provided with.

(Function)
According to the first aspect, since the connection terminal is directly attached to the battery terminal and is not connected by a long wiring, voltage drop due to wiring resistance and a large current is prevented. Further, the connection of the electric wire to the battery terminal and the connection terminal are both electrically connected by a common connection member.

  According to claim 2, in the case where the booster circuit is housed in a housing different from the housing of the electronic control unit, the connection terminal is directly attached to the battery terminal in the same manner as in claim 1, and the connection is made with a long wiring. Therefore, voltage drop due to wiring resistance and large current is prevented.

  In addition, since the booster circuit uses large parts, when the booster circuit is housed together with the housing of the electronic control unit, the size of the electronic control unit itself increases. In this case, when the vehicle is mounted, the layout of the mounting is limited and the degree of freedom is lost. However, according to claim 2, since the booster circuit and the electronic control device are housed in separate housings, the electronic control device itself becomes small, The degree of freedom for mounting the vehicle is widened, which is advantageous for mounting the electronic control device on the vehicle.

According to claim 3, due to the rough surface, the contact surface can bite into the battery terminal and the contact strength can be increased.

According to the fourth aspect, the contact surface of the connection terminal is recessed in a circular arc shape along the cylindrical shape of the battery terminal, so that a contact area can be ensured and an increase in contact resistance is prevented.

As described above in detail, according to the present invention, wiring from the battery to the booster circuit is not necessary, and voltage drop due to wiring resistance and large current is eliminated during operation of the booster circuit. As a result, the output voltage of the booster circuit is reduced. There is an effect that the rise is greatly improved. Moreover, the connection of the electric wire to the battery terminal and the connection terminal can be electrically connected together by a common connection member.

(Implementation form)
Hereinafter, an embodiment in which the present invention is embodied in a motor control device mounted on an automobile, for example, a structure for connecting a booster circuit of an electric power steering control device to a battery will be described with reference to FIGS.

  FIG. 1 is an overall schematic diagram showing a connection structure of a booster circuit, and FIG. 2 is a perspective view showing a connection structure of a housing incorporating a booster circuit to a battery. 3 is a plan view of the connection structure, and FIG. 4 is a perspective view showing the connection structure of the booster circuit to the battery. FIG. 5 is an electric circuit diagram of the booster circuit.

  As shown in FIG. 1, the booster circuit housing 10 is formed in a square box shape and placed on the upper surface of the battery body Bh. A booster circuit 20 is accommodated in the booster circuit housing 10. Since the booster circuit 20 is composed of a known circuit, it will be briefly described with reference to FIG. As shown in FIG. 5, the booster circuit 20 includes a switching element 21, a control circuit 23, a coil 22, a diode D, capacitors C1 and C2, and the like. In this embodiment, the switching element 21 is comprised from MOSFET. Capacitors C1 and C2 are composed of aluminum electrolytic capacitors.

  The DC voltage of the battery B is applied to the coil 22 in the booster circuit 20. The output terminal of the control circuit 23 is connected to the control terminal (the gate terminal in FIG. 5) of the switching element 21. The control circuit 23 outputs a pulse voltage for boosting to a control terminal, and chopper-controls the switching element 21 with this pulse voltage. The switching element 21 is repeatedly turned on and off by the pulse voltage, and the coil 22 repeats grounding / opening. As a result, a high voltage having the same cycle as that of the pulse voltage is generated from the coil 22. This high voltage is smoothed by the capacitor C2 and supplied from the output terminal 25 to the ECU 80 described later.

  A pair of connection terminals 30, 40 project laterally from one side surface along the longitudinal direction of the housing 10. One end of the connection terminal 30 is connected to a plus terminal Ba as a battery terminal of the battery B, and the other end is connected to the coil 22. One end of the connection terminal 40 is connected to a minus terminal Bb as a battery terminal, and the other end is connected to a terminal of the switching element 21.

  Here, a connection structure between the connection terminal 30 and the plus terminal Ba which is a battery terminal will be described. The positive terminal Ba and the negative terminal Bb, which are battery terminals, are formed in a cylindrical shape and project upward from the upper surface of the battery body Bh.

  As shown in FIG. 2, the contact portion 31 that is one end of the connection terminal 30 protrudes upward from the tip of the flat plate portion protruding from the housing 10. The contact portion 31 has a shape in which a cylinder is divided in half along the axial direction, and a contact surface 32 having a semicircular cross section is provided in a side surface. The radius of curvature of the cross-section arc portion of the contact surface 32 is the same as the radius of curvature of the outer peripheral surface of the plus terminal Ba along the cylindrical outer peripheral surface of the plus terminal Ba. A large number of protrusions 32 a are formed on the contact surface 32. As shown in FIGS. 2 and 3, the contact portion 31 is brought into contact with the plus terminal Ba at the contact surface 32. In this state, the contact portion 31 and the plus terminal Ba are clamped by the clamp member 50 as a connecting member. And are tightened together.

  The clamp member 50 includes a pair of sandwiching pieces 52 and 54 whose base portions are integrally connected to each other, and is formed in a bifurcated shape as a whole. The base portions of the sandwiching pieces 52 and 54 have elasticity. The mutually opposing proximal end inner surfaces of the sandwiching pieces 52 and 54 are provided with sandwiching surfaces 53 and 55 that are recessed in a substantially arc shape. When the screwing amount of the bolt 56 that passes through the pinching piece 52 and screwed to the tip of the pinching piece 54 is adjusted against the elasticity of the base portion, the contact portion 31 and the plus terminal Ba are connected to the pinching piece 52. , 54 are fastened together by being sandwiched between the sandwiching surfaces 53, 55. When the bolt 56 is screwed with respect to the sandwiching piece 54, both the sandwiching pieces spread in the anti-pinching direction by the elastic force of the base portion, and the clamp member 50 can be removed. An electric wire L1 is connected to the base of the clamp member 50, and electric power can be supplied to the ECU 80 via the electric wire L.

  The connection structure between the connection terminal 40 and the minus terminal Bb which is a battery terminal is the same as the connection structure between the connection terminal 30 and the plus terminal Ba. For this reason, in the connection terminal 40, about the same structure as the connection terminal 30, what added the 1-digit code | symbol of the connection terminal 30 to the code | symbol of 40 is attached | subjected, and description is abbreviate | omitted. Further, the clamp member 50 used for connecting the connection terminal 40 and the minus terminal Bb is the same as the connection structure of the connection terminal 30 and the plus terminal Ba. Therefore, the same reference numerals are given as shown in FIG. Description is omitted. In FIG. 2, the connection clamping member 50 for connecting the connection terminal 40 and the minus terminal Bb is omitted.

  A connector 58 is provided on one side of the housing 10, and the output terminal 25 and the ground terminal 26 are built in. The ground terminal 26 is connected to the connection terminal 40 as shown in FIG. An electric wire L2 is connected to the output terminal 25 and the ground terminal 26 in the connector 58 through a plug (not shown) (see FIG. 1), and the boosted electric power is supplied to the ECU 80 by the electric wire L2. Although not shown, the ECU 80 is housed in a housing (not shown) separate from the housing 10 because the ECU 80 is disposed at a position separated from the housing 10.

  The ECU 80 is supplied with battery voltage power from the battery B via the electric wire L1. The electric power of the battery voltage is a power source for various circuits (not shown) constituting the ECU 80. Further, the ECU 80 is supplied with the boosted power from the booster circuit 20 via the electric wire L2. The boosted voltage power is supplied to a motor drive circuit (not shown) provided in the ECU 80, and the motor drive circuit is controlled by a control unit (not shown) in the ECU 80, thereby The motor M is driven and controlled.

Now, according to this embodiment, there are the following features.
(1) In this embodiment, the connection terminals 30 and 40 connected to the booster circuit 20 that boosts the battery voltage are directly attached to the plus terminal Ba and the minus terminal Bb (battery terminal) of the battery B. As a result, wiring from the battery B to the booster circuit 20 becomes unnecessary, and voltage drop due to wiring resistance and a large current can be eliminated during the operation of the booster circuit 20. Moreover, the output voltage increase width of the booster circuit 20 can be greatly improved.

That is, at the time of boosting operation of the booster circuit 20, boosting is possible with a smaller battery current than in the prior art.
FIG. 6 is a characteristic diagram of a boosted voltage graph for each ECU input voltage. The horizontal axis represents the duty ratio of the switching element 21 of the booster circuit 20, and the vertical axis represents the boost voltage. As shown in the figure, when the battery voltages are 11V, 12V, and 13V, the battery voltage is boosted according to the duty ratio. However, it can be seen that at any duty ratio, the boosted voltage increases as the battery voltage increases for the same duty ratio. That is, conventionally, the battery voltage applied to the booster circuit is low due to the voltage drop due to the wiring resistance and the large current, but in this embodiment, the voltage drop due to the wiring is eliminated, so the same duty ratio is used. In this case, a boosted voltage larger than the conventional one can be obtained. Further, when considering the case where the voltage is boosted to the same voltage as compared with the case where the voltage drop due to the conventional wiring resistance and large current has occurred, the voltage can be boosted with a smaller battery current during the boosting operation. Therefore, the heat generation of the switching element 21 is reduced as compared with the conventional case, and the switching element 21 and the capacitors C1 and C2 can be reduced in size and cost. Further, conventionally, it is necessary to use a large heat sink for dissipating the heat generated by the switching element. However, according to the present embodiment, heat generation is reduced, so that the heat sink can be downsized.

  FIG. 7 is a characteristic diagram of the boosting efficiency graph and the battery current graph. As shown in the figure, the duty ratio of the chopper drive of the switching element 21 increases as the duty ratio increases. Conventionally, due to voltage drop due to wiring resistance and large current, in order to increase the boost voltage, it is necessary to flow a large amount of battery current, and as a result, there is a problem that boost efficiency is lowered. In the present embodiment, the voltage drop due to the wiring resistance and the large current is eliminated, and the voltage drop only needs to be that of the connection terminal 30, so that the boosting efficiency is also improved.

  Conventionally, in anticipation of voltage drop due to wiring resistance and large current, measures such as increasing the inductance of the coil 22 in order to increase the boost voltage, or using a bus bar to reduce the circuit board pattern resistance as much as possible. I need to take it. For this reason, there has been a problem of cost increase. On the other hand, in the present embodiment, it is not necessary to take such measures, and the cost can be reduced.

  (2) In the present embodiment, the booster circuit 20 is housed in a housing 10 different from a housing (not shown) that houses an ECU 80 that includes a control unit (not shown) that controls the motor M (actuator). The connection terminals 30 and 40 project outward from the housing 10 that houses the booster circuit 20, and are directly attached to the plus terminal Ba and the minus terminal Bb of the battery B. As a result, in the case where the housing 10 of the booster circuit 20 different from the housing of the ECU 80 is provided, the same effect as the above (1) is obtained.

  Further, since the booster circuit 20 uses large parts, the size of the ECU 80 itself increases when the booster circuit is housed together with the housing (not shown) of the ECU 80. In this case, when the vehicle is mounted, there is a problem that the mounting layout is limited and the degree of freedom is lost. However, in the present embodiment, since the ECU 80 and the booster circuit 20 are housed in separate housings, the ECU 80 itself is small, and the degree of freedom of mounting the ECU 80 on the vehicle is widened, which makes it advantageous to mount the ECU 80 on the vehicle.

  (3) In the present embodiment, the clamp member 50 to which one end of the electric wire L1 is connected is detachably attached to the positive terminal Ba and the negative terminal Bb of the battery B, and the connection terminals 30 and 40 are attached by the clamp member 50. Was sandwiched between the positive terminal Ba and the negative terminal Bb of the battery B. As a result, the connection of the electric wire L1 to the plus terminal Ba and the minus terminal Bb of the battery B and the connection terminals 30 and 40 can be electrically connected by the common clamp member 50.

  (4) In the present embodiment, the contact surfaces 32 and 42 of the connection terminals 30 and 40 that are in contact with the outer peripheral surfaces of the plus terminal Ba and the minus terminal Bb are formed rough. As a result, due to the rough surface, the contact surfaces 32 and 42 bite into the outer peripheral surfaces of the plus terminal Ba and the minus terminal Bb, and the contact strength can be increased. In addition, since the contact strength can be increased, the vehicle is also resistant to vibration during driving of the automobile, that is, vibration resistance can be increased.

  (5) In this embodiment, the plus terminal Ba and the minus terminal Bb of the battery B are formed in a cylindrical shape. On the other hand, the connection terminals 30 and 40 include contact surfaces 32 and 42 that are recessed in a circular arc shape along the cylindrical outer peripheral surfaces of the plus terminal Ba and the minus terminal Bb. As a result, a contact area between the connection terminals 30 and 40 and the plus terminal Ba and minus terminal Bb of the battery B can be secured, and an increase in contact resistance can be prevented.

( Reference example )
Next, a reference example will be described with reference to FIGS. In addition, about the same structure as the said embodiment, the same code | symbol is attached | subjected, the description is abbreviate | omitted and it demonstrates centering on a different location.

In the reference example , the configuration of the connection terminal is different from that of the above embodiment. As shown in FIG. 9, the connection terminals 60 and 70 protrude from both end surfaces of the housing 10 in the longitudinal direction. A clamp portion 150 is provided at the distal ends of the connection terminals 60 and 70. The configuration of the clamp unit 150 is a configuration in which the configuration in which the electric wires L1 are provided at the base portions of the sandwiching pieces 52 and 54 in the configuration of the clamp member 50 of the above embodiment is omitted, and the other configurations are the same. Therefore, with the clamping portion 150 of the reference example, the configuration corresponding to the configuration of the clamp member 50 of the embodiment, the code obtained by adding code to 100 as those in the configuration of the clamp member 50 in the embodiment Therefore, the description is omitted. Accordingly, the clamp unit 150 includes sandwiching pieces 152 and 154 and bolts 156.

  A connecting portion 160 protrudes laterally from the outer side of the sandwiching piece 154. A connecting portion 161 protrudes upward from the distal end of the connecting portion 160. The connecting portion 161 is formed in a cylindrical shape so as to have the same shape and the same diameter as the plus terminal Ba and the minus terminal Bb.

Although not shown in the drawing, the clamp member 50 of the above embodiment is detachably attached to each connection portion 161, and battery voltage power is supplied from the battery B to the ECU 80 via the electric wire L <b> 1.

Now, according to the reference example, (1) of the embodiment, there are other, the following features of the advantages of the (2).
(1) In the reference example , the connection terminals 60 and 70 are provided with a clamp portion 150 that is detachably attached to the plus terminal Ba and the minus terminal Bb, and the connection portion 161 having the same shape as the plus terminal Ba and the minus terminal Bb is provided. I prepared. As a result, the clamp member 50 provided for connection with the plus terminal Ba and the minus terminal Bb can be used as it is.

(2) In the reference example , the connecting portion 161 extends in the same direction as the protruding direction of the plus terminal Ba and the minus terminal Bb protruding from the battery body Bh. As a result, the connecting portion 161 is extended in the same direction as the protruding direction of the plus terminal Ba and the minus terminal Bb, so that the electric wire L1 extended from another power supply target can be connected as in the prior art. Wiring changes can be minimized.

In addition, you may change embodiment of this invention as follows.
In the above embodiment, the switching element 21 of the booster circuit 20 is a MOSFET, but it may be replaced with a bipolar transistor.

  ○ The connecting member is not limited to the clamp member 50, and any connecting member may be used. In particular, those that are detachably attached directly to the battery terminal are preferable.

1 is an overall schematic diagram showing a connection structure of a booster circuit according to an embodiment embodying the present invention. The perspective view which shows the connection structure to the battery of the booster circuit of one Embodiment. The top view of a connection structure similarly. The perspective view which similarly shows the connection structure to the battery of a booster circuit. The electric circuit diagram of a booster circuit. The characteristic figure of the step-up voltage graph according to ECU input voltage. The characteristic figure of a boosting efficiency graph and a battery current graph. The perspective view which shows the connection structure to the battery of the booster circuit of a reference example . The top view of a connection structure similarly. Explanatory drawing which shows the connection of the conventional booster circuit and a battery.

Explanation of symbols

Ba ... Plus terminal (battery terminal)
Bb ... Negative terminal (battery terminal)
L1 ... Electric wire 10 ... Housing 20 ... Booster circuit 30, 40 ... Connection terminal 32, 42 ... Contact surface 50 ... Clamp member (connection member)
150 ... Clamp part 161 ... Connection part

Claims (4)

A connecting member connected to one end of the electric wire is detachably attached to the battery terminal of the battery, and the connecting terminal connected to the booster circuit for boosting the battery voltage is directly attached to the battery terminal by the connecting member. A structure for connecting a booster circuit to a battery. The booster circuit is housed in a housing separate from a housing housing an electronic control device including a control unit that controls an actuator, and the connection terminal protrudes from the housing housing the booster circuit to the battery. 2. The structure for connecting a booster circuit to a battery according to claim 1, wherein the structure is directly attached to a terminal. 3. The structure for connecting a booster circuit to a battery according to claim 2, wherein the connection terminal has a rough contact surface that contacts the outer peripheral surface of the battery terminal when connected to the battery terminal. . The said battery terminal is formed in the column shape, The said connection terminal was provided with the contact surface dented in the cross-sectional arc shape along the column-shaped outer peripheral surface of the said battery terminal. A structure for connecting the described booster circuit to a battery.

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