JPS6350872Y2 - - Google Patents

Description

[Detailed description of the invention] [Purpose of the invention] (Field of industrial application) The present invention houses a power transistor used to adjust the rotation speed of a fan in an automobile air conditioner, and The present invention relates to a power transistor storage body designed to radiate heat, and particularly to a harness fixing structure for fixing a harness to the storage body.

(Prior Art) Generally, various transistors are incorporated into the electric circuit of an automobile air conditioner, and among these transistors, there is one that controls the rotational speed of the motor in particular to adjust the amount of air discharged by the fan. A so-called power transistor is used as a power transistor. FIG. 1 is a circuit diagram showing a part of a circuit incorporating a power transistor applied to an automobile air conditioner, etc. The power transistor T consists of a small capacity transistor T1 and a large capacity transistor T2. have. In this circuit diagram, one end of the fan motor M is connected to a power supply B, the other end is connected to the collector terminal of a transistor T2 via a resistor R, and the emitter terminal of the transistor T2 is grounded. ing. Further, a signal line 30 through which an output signal from an auto amplifier (not shown) or the like of an automobile air conditioner is transmitted is connected to a base terminal of a transistor T1, and a collector terminal of the transistor T1 is connected downstream of the fan motor M. side, and the emitter terminal is connected to the transistor T2.
are connected to the base of each. According to the fan motor control circuit of an automobile air conditioner incorporating such a power transistor T, when a passenger operates a fan motor rotation speed control switch (not shown), this operation command causes the autoamplifier to respond to the operation command. A corresponding command signal flows through the signal line 30 to the transistor T1, and as a result, a minute current having a current value corresponding to the command signal flows from the collector terminal side to the emitter terminal side of the transistor T1. When this minute current flows to the base terminal of the transistor T2, a large current corresponding to the minute current value flows from the collector terminal to the emitter terminal of the transistor T2, thereby causing the fan motor to M rotates at a rotational speed according to the command signal from the autoamplifier.

Further, this power transistor T is a type of resistor and generates heat due to current. For this reason,
The power transistor T, as shown in FIG.
As shown in FIG. 3, the heat dissipation fins 21 are installed so as to protrude into a duct through which air flows, and perform forced cooling of the power transistor T.

As shown in FIGS. 2 and 3, the storage body 1 for the power transistors T includes
A harness 4 is fixed by screws 3 to the top surface 2 of the storage body 1 which houses the storage body 1 (not shown). This harness 4 consists of a flat base 5, an annular grip 7 that stands upright from the base 5 and grips a plurality of conductive wires 6, and the plurality of conductive wires 6, and the harness 4 includes: It is attached to the upper surface 2 of the storage body 1 by screwing the base 5 through the terminal 9 of the ground wire 8 and the washer 10 while holding the ground wire 8 with the screw 3. The fixing structure of such a harness is
It is applied to the connecting portions of the base, collector, and emitter terminals of the two transistors T1 and T2 shown in FIG.

(Problem to be solved by the invention) However, in such a conventional harness fixing structure, a second
When a force is applied in the direction of arrow F in the figure, screw 3 loosens,
The contact resistance between the harness 4 and the storage body 1 increases. When the resistance value of the connection between the transistor T and the harness 4 becomes larger than a predetermined value, for example, when the base terminal of the transistor T is connected, the input current value to the transistor T decreases, and the current value input to the transistor T becomes smaller. The value of the flowing current becomes smaller than the predetermined value. Therefore, fan motor M
The current value flowing through the fan motor switch also decreases, causing the problem that the fan motor switch operates at a lower rotation speed than the fan motor switch operated by the passenger.

Further, for example, if the resistance value of the connection portion between the collector terminal or emitter terminal of the transistor T2 and the harness 4 increases, the transistor T2
Since a large current is flowing through the contact portion, this contact portion generates abnormal heat, resulting in thermal breakdown of the transistor T2.

In other words, due to the above-mentioned characteristics of the power transistor T, if the resistance value of the fixed portion of the conductive wire connecting the power transistor T changes even slightly, the fixed part of the conductive wire connecting the power transistor T will be damaged by the controlled object controlled by the power transistor T, that is, the automobile. There is a problem that the rotation speed of the fan motor M of the air conditioner cannot be maintained at a desired rotation speed, and furthermore, there is a problem that the durability of the power transistor T is reduced due to abnormal heat generation at the contact portion.

This power transistor T is the 13th
As shown in the figure, they are usually installed in the duct through which the air of an automobile air conditioner flows, for example, in the downstream part of the blower case, and they are housed in the part of the lower part of the instrument panel that contacts the dashboard panel. Therefore, as long as the harness of the power transistor T is securely attached, it will not be touched by human hands after being stored, so there is almost no risk that the screws will come loose.

However, as is clear from Fig. 13, the power transistor T is attached so as to protrude from the blower case, etc., and so when the automotive air conditioner is stored in the vehicle interior, the worker may often strike the power transistor T with a tool or the like during the work. If the harness is struck with a tool, the harness may easily move. If the harness is struck and moved in this way, the threaded portion of the harness may become loose, and in an object that is constantly subjected to vibration, such as an automobile, the loosening of the threaded portion may accelerate over time.

Furthermore, the above-mentioned blows to the harness are usually done unconsciously, and furthermore, once the power transistor is installed, it is not only out of sight but also in an inaccessible location. Therefore, when the abnormal rotation of the fan or the abnormal air conditioning caused by the loosening of the harness occurs, the crew members have no idea what is causing the problem, and they end up tampering with unrelated areas, causing further failures. Something very inconvenient had happened.

These problems can be solved by using a fitting socket for the harness connection structure, but
If such a structure is adopted, a new problem arises in that it inevitably leads to an increase in cost.

The present invention was developed in view of the drawbacks and problems associated with the conventional technology described above, and by preventing the rotation of the harness connected to the power transistor, it is possible to accurately control the controlled object of the power transistor. The purpose is to achieve this in a structure that is as simple and inexpensive as possible.

[Structure of the invention] (Means for solving the problem) The present invention for achieving the above object uses a harness consisting of a base on a flat plate and a conductor grip part protruding from the base for use in an air conditioner for an automobile. A harness fixing structure in which a power transistor for controlling rotation of a fan motor is fixed to a surface of a storage body with screws, includes a locking part that engages with a periphery of a base of the harness to prevent rotation of the harness. The harness fixing structure is characterized in that it is formed on the surface of the storage body.

(Function) In the present invention configured as described above, the harness is rotated by engaging the locking portion formed on the surface of the storage body housing the power transistor with the periphery of the base of the harness. There's nothing to do,
This strengthens the connection between the power transistor and the harness.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 4 is a perspective view showing the harness fixing structure according to the first embodiment of the present invention, and FIG. 5 is a view taken in the direction of the arrow in FIG. 4, and shows the conventional harness fixing structure shown in FIGS. The same parts are given the same reference numerals.

The harness fixing structure shown in FIGS. 4 and 5 can be applied, for example, to a control circuit that controls the rotation speed of a fan motor M of an automobile air conditioner as shown in FIG. It is used for connecting the base terminal, collector terminal, emitter terminal, etc. of each transistor T1, T2 of the transistor T. In this figure, a base 5 of a harness 4 to which ends of a plurality of conductive wires 6 are connected is attached to the upper surface 2 of the storage body 1 that houses a power transistor T (not shown).
A pair of parallel long walls 11 are formed with an interval slightly wider than the width. Further, the harness 4 is screwed with the screw 3 while holding the terminal 9 of the ground wire 8 and the washer 10 therebetween. The long wall 11 comes into contact with both end edges 13, which are the peripheral edges of the harness 4, so that even if a force in the direction F shown in FIG. 4 acts on the base 5 of the harness 4, the harness 4 does not rotate. It's becoming like that.

According to the harness fixing structure of this embodiment configured in this way, with the base 5 of the harness 4 positioned between the two long walls 11, 11, the screw 3
By fixing the harness 4 to the storage body 1, even if the force shown by the arrow F in FIG. They do not touch each other and rotate. Therefore, without the screw 3 loosening and the resistance value of the contact portion changing, the current value flowing through the power transistor T becomes a predetermined current value according to the operator's operation command, and the rotation speed of the fan motor M is controlled. is always performed accurately, and thermal damage to the transistor T does not occur.

The harness fixing structure of the present invention is not limited to the first embodiment, and can be modified in various ways.

FIG. 6 is a perspective view showing a harness fixing structure according to a second embodiment of the present invention, and FIG. 7 is a view taken along the arrow in FIG.
A pair of parallel long grooves 14 and 15 are formed on the upper surface 2 of the storage body 1 that houses the storage body 1 . On the other hand, the width of the four base parts 5 of the harness is formed wider than the width of the base part 5 of the first embodiment described above, and both side edge parts 16, 16 of this base part 5 extend diagonally downward, and the long groove 14, 15 so as to be able to fit therein.
The base 5 in this embodiment is formed into the above-described shape by pressing the center part of the U-shaped part downward as shown by the imaginary line in FIG.
The inside of 6 will curve upwards somewhat.

According to the harness fixing structure according to the second embodiment configured as described above, since both end edges 13, 13 of the base 5 of the harness 4 engage with the long grooves 14, 15,
Even if a force in the anti-fastening direction of the screw 3 screwing the harness 4 is applied to the harness 4, the harness 4 does not rotate, and the same effect as in the first embodiment described above is achieved.

8 and 9 are perspective views showing a harness fixing structure according to a third embodiment of the present invention, and FIG. 9 is a sectional view taken along the line - in FIG. 8, showing a power transistor T (not shown). A rectangular hole 17 is bored approximately in the center of the upper surface 2 of the stored storage body 1. On the other hand, the tip 18 of the base 5 of the harness 4
is formed to have a slightly narrower width, is bent to extend downward, and can be inserted into the hole 17 of the storage body 1. Incidentally, since this tip portion 18 is formed by pressing from above into an L-shape shown by imaginary lines in FIG. 8, it will be slightly curved upward.

Even in the harness fixing structure according to the third embodiment configured as described above, when the distal end 18 of the base 5 of the harness 4 hanging downward is inserted into the hole 17, the base 5 of the harness 4 is inserted into the hole 17. If it is screwed onto the upper surface 2 of the storage body 1 with the screw 3, rotation of the harness 4 is prevented. Furthermore, even if the tip end 18 of the base 5 is inserted obliquely into the hole 17, the orientation will be corrected when screwing it in with the screw 3.

FIG. 10 is a perspective view showing a harness fixing structure according to a fourth embodiment of the present invention, in which a convex portion 19 is provided at the end of the upper surface 2 above the storage body 1 that accommodates a power transistor T (not shown). is formed,
This convex portion 19 is adapted to come into contact with the front end portion of the base portion 5 when the harness 4 is fixed. Even in the case of this configuration, the same effects as those of the first to third embodiments described above are achieved, and thereby the harness is prevented from rotating relative to the storage body.

FIG. 11 is a perspective view showing a harness fixing structure according to a fifth embodiment of the present invention.
A groove 20 is provided in the groove 20, and a screw hole is bored in the bottom surface of the groove 20 so that the base 5 of the harness 4 can be fixed with a screw 3. Even in the case of this configuration, the same effects as in the first to fourth embodiments described above are achieved, and thereby the harness is prevented from rotating relative to the storage body.

[Effects of the invention] As described above, according to the invention, a locking portion is formed on the surface of the storage body to engage with the periphery of the base of the harness and prevent rotation of the harness.
It is possible to prevent the screws from loosening due to the rotation of the harness, which allows the fan rotation of the automotive air conditioner to operate properly, and improves the durability of the power transistor, which in turn improves the performance of the vehicle. Indoor air conditioning can be achieved appropriately, allowing occupants to concentrate on driving in comfort. Moreover, it has the practical effect of being able to achieve such effects with an extremely simple and inexpensive structure.

[Brief explanation of the drawing]

Fig. 1 is a circuit diagram showing the positional relationship between the fan motor and the power transistor, Fig. 2 is a perspective view showing the conventional harness fixing structure, Fig. 3 is a view taken along the arrow in Fig. 2, and Fig. 4 5 is a perspective view showing a first embodiment of a harness fixing structure according to the present invention, FIG. 5 is a view taken along the line of FIG. 3, and FIG. 7 is a view taken along the line in FIG. 6, FIG. 8 is a perspective view showing the third embodiment of the present invention, FIG. 9 is a sectional view taken along the line - in FIG. 7, and FIG. FIG. 12 is a perspective view of the fifth embodiment, FIG. 12 is a perspective view showing the entire power transistor, and FIG. 13 is an explanatory diagram of how the power transistor is attached to an air conditioner for an automobile. 1...container, 3...screw, 4...harness,
5...Base of harness, 11, 12...Long wall, 1
3... Side edge of base, 14, 15... Long groove, 16...
...Side edge of the base, 17...hole, 18...tip of the base.

Claims (1)

[Claims for Utility Model Registration] (1) A harness consisting of a base on a flat plate and a conductor grip part protruding from the base is screwed onto the surface of a housing for a power transistor for controlling the rotation of a fan motor of an automotive air conditioner. In the harness fixing structure, a locking part is formed on the surface of the storage body to engage with the periphery of the base of the harness and prevent rotation of the harness. Fixed structure. (2) The harness fixing structure according to claim 1, wherein the locking portion is a pair of parallel walls that abut against both side edges of the base of the harness. (3) The harness according to claim 1, wherein both edges of the base of the harness are bent downward, and a pair of long grooves into which the bent edges fit are formed on the surface of the storage body. Fixed structure. (4) The harness fixing structure according to claim 1, wherein one end edge of the base of the harness is bent downward, and a hole into which the bent edge is inserted is formed on the surface of the storage body. .