JPH0429117Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to an improvement in an air blowing control device that controls the amount of air blown by changing the voltage applied to a fan motor of an air conditioner for an automobile.

(Prior Art) In general, a blower control device that controls the rotation of a blower of an automobile air conditioner sets the number of rotations of a fan motor to, for example, high speed rotation (hereinafter referred to as Hi), mid-speed rotation (hereinafter referred to as M), or low speed rotation (hereinafter referred to as M). The control circuit connects a plurality of resistors having a predetermined resistance value in series, and changes the total resistance value of these resistors as appropriate to control the voltage applied to the fan motor. It has a resistance section that changes the

More specifically, as shown in FIG. 4, this air blow control device connects the current fuse F ₁ of the automobile air conditioner to the base line L to which one end of the battery B is connected.
A fan motor M is connected through the fan motor M, and a resistor section 1 is connected to the fan motor M. This resistance section 1 is connected via a temperature fuse _F2 of a resistance R (a general term for _R1 to _R3 ) and a plurality of resistances R having a predetermined resistance value, or
It is constructed so that it can be electrically connected to the control switch Cs without going through _F2 and the resistor R.

In this motor circuit, the control switch
If you operate Cs and select the terminals T that determine the fan speed, such as high speed (Hi), medium high speed (MH), medium low speed (ML), and low speed (LO) terminals T ₁ to ₄ , as appropriate, The fan speed can be changed to multiple levels.

The temperature fuse _F2 is used to protect the blower by cutting off the motor circuit when the resistor R generates abnormal heat when an abnormality occurs such as when the motor is locked, and is blown by this heat.

The resistance R is cooled by the air flowing through the air passage D of the automobile air conditioner, but recently, for example, as shown in FIG. The heat of the resistor R is removed by the wind blown from the fan f in the fan scroll Fs.

In order to improve the heat dissipation of this resistor R, as shown in FIGS. 6A, B, and C, a pair of support plates S ₁ and S ₂ made of phosphor bronze spring material protrude from the top of the base 2. A temperature fuse F ₂ is attached to the tip of the supporting plates S ₁ and S 2 against the elastic force of the supporting plates S 1 and S ₂ , and this temperature fuse F ₂ is surrounded from three sides by each resistance R formed in a coil shape. The length l of the leg portion Ra of the resistor R is increased to protrude from the base 2 into the air path D.

In this way, the resistance R can be brought into sufficient contact with the air, and the heat of this resistance R can be quickly dissipated, and when an abnormal current flows through the resistance R such as when the motor is locked, this resistance The temperature fuse _F2 is blown by the heat generated by R, cutting off the motor circuit and protecting the blower (see Japanese Utility Model Publication No. 18728/1983).

(Problem to be solved by the invention) However, when the blower control device configured in this way is installed in a place where air is blown by a fan, it becomes a resistance to the wind and reduces the amount of air blown through the air path D. There is a risk that wind noise may also be generated. Furthermore, if the air conditioner is installed in a corner of an automobile air conditioner where there is little air circulation in order to reduce this air blowing resistance, it will be difficult to remove heat and the heat dissipation will be reduced.

This blower control device also includes a leg portion Ra of each resistor R or a support plate S ₁ of the temperature fuse F ₂ ,
Since S ₂ is long, it occupies a large space and also has the drawback of being easily deformed by external forces.

Furthermore, when installing the temperature fuse F ₂ , it must be installed against the elasticity of the support plates S ₁ and S ₂ , making the installation process extremely troublesome, and furthermore, once it is blown, it cannot be used again. Repair work has become a tedious task.

Note that there is also a device in which the resistance R is provided in a cage-shaped fuse box (Utility Model 59-
(See Japanese Patent Publication No. 186110), in this case, in addition to the drawbacks of the aforementioned reduction in heat dissipation and the generation of wind noise, there is also the problem that the assembly work when assembling the whole thing becomes troublesome.

The present invention was developed by focusing on the above-mentioned problems, and has low air flow resistance, extremely high heat dissipation of the resistance, and easy assembly of the temperature fuse and the entire device, making it a cost-effective automobile. The purpose of the present invention is to provide a ventilation control device for an air conditioner.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides an air conditioner for automobiles by appropriately changing the total resistance value of a resistance section in which a plurality of resistors are electrically connected in series. A temperature fuse is configured to control the voltage applied to a motor for rotating the blower fan of the device and control the rotation speed of the motor, and is blown by abnormal heat generation of the resistor to electrically interrupt the motor circuit. In the air blow control device for an automotive air conditioner, the resistance portion is formed by printing a resistance member constituting the resistance in a predetermined pattern on a flat electrically insulating substrate having a heat-resistant layer formed on a thin iron plate. The temperature fuse, which melts when the temperature exceeds a predetermined temperature, is detachably attached directly to the resistor pattern.

(Function) If such a means is adopted, the contact area between the resistance and the air will increase, resulting in an air blow control device with extremely high heat dissipation.Moreover, it will not take up much space, so it can be installed anywhere, and can be installed in a flat structure. Therefore, it is possible to obtain a device that does not cause air flow resistance, and the efficiency of replacing the temperature fuse and assembling the entire device is greatly improved.

(Example) An embodiment of the present invention will be described below.

FIG. 1 is a perspective view of essential parts showing an embodiment of the present invention;
FIG. 2 is a sectional view taken along the - line in FIG. 1, and FIG. 3 is an exploded perspective view showing the installed state of the same embodiment.
Components that are the same as those shown in FIGS. 4 to 6 are designated by the same reference numerals, and their descriptions will be omitted.

In this air blow control device 10, a temperature fuse _F2 is mechanically attached to the resistance section 11 in a detachable manner.

This resistor section 11 is constructed by printing a resistor member constituting the resistor R in a predetermined pattern on a rigid flat electrically insulating substrate 12, and this is formed by printing a fan scroll Fs as shown in FIG.
It is attached to the ceiling board Ft inside the fan motor M and controls the rotation speed of the fan motor M.

In more detail, the resistor part 11 is made of a so-called enamel plate, which has a heat-resistant layer 14 made of glass or the like electrically glazed on a steel plate 13 serving as a base material, as shown in FIGS. 1 and 2. be. This board 12
The resistor R is provided above, and the surface is covered with a heat-resistant layer 15 made of glass or the like to prevent dust from adhering from the outside.
This resistance R (general term for R ₁ to ₃ ) consists of a first resistance R ₁ , a second resistance R ₂ , and a third resistance R ₃ , and in forming the circuit of this resistance R on the substrate 12, After printing a thick film paste on the substrate 12 so that the resistance value of each resistor R becomes a predetermined value, it is fired. And each of these resistances R ₁ to ₃
Each of the terminals T (generic name of T ₁ to ₄ ) described above is connected to the end portion of A resistor section 11 is used.

The temperature fuse _F2 is connected between the Hi terminal _T1 and the resistor _R1 , as is clear from the electrical circuit diagram in FIG. In this embodiment, as shown in FIG. 1, one end of the conductor 16 electrically connected to the temperature fuse _F2 is connected to the Hi terminal _T1 ,
The other end is connected to the fuse terminal Tf, which is substantially the same as that shown in FIG. 4 above. Moreover, this temperature fuse F ₂ is mechanically and removably attached with screws 17 so as to be located on the resistance R printed on the resistance part 11 so that the heat generated by the resistance R is immediately transferred. .

In addition, when installing this temperature fuse F ₂ , the screws should support a leaf spring (not shown), and this leaf spring will connect the temperature fuse F 2 to the temperature fuse F ₂ .
The structure may be such that it is elastically held under pressure.
This makes it extremely easy to replace the temperature fuse _F2 after the temperature fuse _F2 has blown out.

Also, this resistance section 11 is fan scrolled Fs
To attach the terminals to the fan scroll Fs, as shown in FIG. Screw insertion hole 18 opened in , ceiling plate of Fan Scroll Fs
Insert into the bell mouth 19 of Ft and fan scroll Fs and tighten and secure.

Next, the action will be explained.

The resistance R of the ventilation control device 10 configured as described above is controlled by changing the total resistance value as appropriate by operating the control switch Cs shown in FIG.
For example, the case where the control switch Cs selects the LO position will be described.

When control switch Cs is connected to LO terminal _T4 , the current from battery B is transferred to the current fuse.
F ₁ enters the Hi terminal T ₁ in FIG. 1 via the motor M.

This current further flows in the order of Hi terminal T ₁ → first resistance R ₁ → second resistance R ₂ → third resistance R ₃ → LO terminal T ₄ .

In this case, the first, second, and third resistances
When a current passes through R ₁ to R ₃ , this resistance section 11 generates heat, and this heat is transmitted to the substrate 12 .

However, the resistance R is widely arranged over the entire substrate 12, and since the substrate 12 is flat and has a large area, and the contact area with the air is large, the transmitted heat is transferred to the fan scroll Fs. Heat is quickly radiated by the air passing through the air path D.

Furthermore, since the resistance R has a flat structure and its surface area is extremely large compared to conventional coil type resistors, the resistance R itself has a high heat dissipation property, and the heat dissipation property of the resistance section 11 is also high. is significantly improved.

Next, when the control switch Cs selects the Hi position, the current entering the Hi terminal _T1 in Fig. 1 does not flow to the resistance R side, but returns to the battery B from the control switch Cs, and
When the control switch Cs selects the M _H position, the current flows from the Hi terminal T ₁ → the first resistance R ₁ → the M _H terminal T ₃ , and furthermore,
When the control switch Cs selects the M _L position, the current flows from the Hi terminal T ₁ → the first resistance R ₁ → the second resistance R ₂ → the M _L terminal T ₃ ,
The fan speed is commensurate with each current.

In this case, since the resistance part 11 is extremely flat and is attached closely to the ceiling plate Ft of the fan scroll Fs, it will not act as ventilation resistance for the air flow flowing in this air path D. There is no reduction in quantity. Also, there is no wind noise.

Furthermore, in the ventilation control device 10, if the fan motor M is locked for some reason, the temperature of the resistance R of the ventilation control device 10 becomes abnormally high, but this high temperature is immediately transferred to the temperature fuse _F2. It will be transmitted and this will be fused. The power supply to the motor M is cut off by this blowout, and even if the above-mentioned abnormal situation occurs, various inconvenient situations accompanying this can be immediately avoided.

After the motor stops and the heat generated by the resistor R subsides, the cause of the motor lock is removed and the temperature fuse _F2 is replaced with a new one, allowing normal air blowing operation to resume.

In this case, since the temperature fuse F ₂ is blown out on the heat-resistant layer 15, no inconvenience will occur, and the temperature fuse F ₂ can be replaced by loosening the screw 17 and then replacing the temperature fuse F ₂ . All you have to do is install it and retighten it, eliminating the need for brazing work, etc., as in the past, and eliminating the need for troublesome work. In addition, conventional brazing, cages, etc. are not required, the assembly work is extremely easy, and the number of parts is small, which is advantageous in terms of cost.

Although the resistor section 12 is installed inside the fan scroll _fs , the present invention can be applied not only to such a place but also to
Because of its good heat dissipation properties, it can be installed anywhere on the inner wall of the air duct of an automotive air conditioner, greatly increasing the flexibility of installation location.

[Effects of the invention] As is clear from the above explanation, according to the invention, the resistance part is constructed by printing the resistance members constituting the resistance in a predetermined pattern on a rigid flat electrically insulating substrate. This results in a flat resistance part, which increases the contact area between the resistance and the air, greatly improving heat dissipation, and does not create air resistance.Moreover, it does not take up much space, so it can be installed anywhere. There is no need to reduce the amount. In addition, a temperature fuse that melts when the temperature exceeds a predetermined temperature is mechanically attached and detached on the resistor, and this temperature fuse is connected to the motor circuit, eliminating the need for brazing work and improving workability during assembly and maintenance. It has excellent properties and is advantageous in terms of cost.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of essential parts showing an embodiment of the present invention, FIG. 2 is a sectional view taken along the line - in FIG. 1,
Fig. 3 is a perspective view showing the installed state of the same embodiment, Fig. 4 is a circuit diagram of the air blow control device of a general automobile air conditioner, and Fig. 5 shows the installed state of the air blow control device. The perspective view shown in FIGS. 6A, 6B, and 6C are a plan view, a side view, and a sectional view of essential parts showing the actual structure of a conventional resistor. 10...Blower control device, _F2 ...Temperature fuse,
11...Resistance part, 12...Electrical insulating board, M...
Motor, R...Resistance.

Claims (1)

[Scope of utility model registration request] By appropriately changing the total resistance value of the resistance section 11 in which a plurality of resistances R are electrically connected in series, the voltage applied to the motor M for rotating the blower fan of the automobile air conditioner is controlled, and the voltage applied to the motor M is controlled. In the air blow control device for an air conditioner for an automobile, the temperature fuse _F2 is configured to control the rotation speed and is blown by abnormal heat generation of the resistor R to electrically interrupt the motor circuit. 11 is formed by printing the resistance member constituting the resistance R in a predetermined pattern on a flat electrically insulating substrate having a heat-resistant layer formed on a thin iron plate. 1. A blower control device for an air conditioner for an automobile, characterized in that the temperature fuse _F2 , which melts when the temperature exceeds , is removably attached directly to the temperature fuse F2.