JPH073560Y2 - Blower control device for automobile air conditioner - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial field of application) The present invention relates to a blower control device that controls the amount of air blown by a blower by changing the voltage applied to a fan motor of an automobile air conditioner. In particular, it relates to improvement of a thermal fuse attached to the blower control device.

(Prior Art) In a blower control device for an air conditioner for an automobile, the problem of blow resistance and wind noise, which are the drawbacks of the conventional coil resistance (for example, see Japanese Utility Model Publication No. 56-18,728), can be solved. A blower control device having a flat structure can be cited (see, for example, Japanese Utility Model Laid-Open No. 63-171,213).

This air flow control device called flat resistance,
By printing a plurality of resistances on a flat substrate to form a resistance circuit that connects the resistances in series, each terminal is connected to each resistance, and the terminal is appropriately selected by a fan switch. By changing the total resistance of the resistance circuit,
The voltage applied to the fan motor of the automobile air conditioner is changed to control the rotation speed of the motor in multiple stages.

Further, the blower control device has a temperature fuse for preventing a defect such as a burning of the fan motor due to the abnormal heat generation of the resistance.

As shown in FIGS. 7 (a) and 7 (b), the thermal fuse F ₁ includes a through hole 7 (conductive cut-off portion) for cutting off the continuity of the circuit of the resistance R printed on the substrate 3, and the through hole. When the resistance is abnormally heated as in the case of an abnormality such as a motor lock, it is melted by the heat generation and the power supply to the fan motor is cut off. ing.

In the figure, reference numeral 8 is an iron plate as a base material, 9 is a heat resistant insulating layer, and 10 is a glass heat resistant insulating layer made of glass or the like.

(Problems to be solved by the invention) However, as described above, since the thermal fuse is an important safety device that avoids various problems caused by abnormal heat generation of resistance, it is more important than the conventional thermal fuse described above. It is desired to develop a thermal fuse having a better fusing response to abnormal heat generation of resistance.

The present invention has been made in view of the above situation, and when an abnormal heat generation occurs in the resistance, the temperature fuse is immediately blown to cut off the power supply to the fan motor. It aims at providing the ventilation control device of this.

[Configuration of Device] (Means for Solving the Problem) A first device for achieving the above object is to print a plurality of resistances on a flat electrically insulating substrate and electrically connect the resistances in series. The resistance of the connected resistance circuit is changed to control the voltage applied to the fan motor of the vehicle air conditioner, and the rotation speed of the motor is controlled in multiple stages. In a blower control device for an automobile air conditioner, which comprises a temperature fuse that blows off due to heat generation and shuts off power supply to the motor, the temperature fuse includes a conduction cutoff portion that cuts off conduction of the resistance circuit, And a solder for bridging the conduction cutoff portion to bring the resistance circuit into conduction, and the resistance end portions facing each other in the conduction cutoff portion are connected to each other. It is characterized in that it is composed of a material layer having better wettability than a resistance base material, and that the solder in a molten state due to the abnormal heat generation of the resistance is easily absorbed by the end portion. It is a blower control device for an air conditioner for an automobile.

A second invention for the same purpose is to print a plurality of resistances on a flat and electrically insulating substrate and change the total resistance value of a resistance circuit in which the resistances are electrically connected in series to change the resistance value for an automobile. A temperature fuse configured to control the voltage applied to the fan motor of the air conditioner to control the rotation speed of the motor in multiple stages, and to cut off the power supply to the motor due to abnormal heat generation of the resistance. In a ventilation control device for an air conditioner for an automobile, comprising: the temperature fuse, a conduction cutoff portion for cutting off conduction of the resistance circuit, and a solder for bridging the conduction cutoff portion to conduct the resistance circuit. And at least one of the ends of the resistance facing each other in the conduction cutoff portion is formed in a fine concavo-convex shape. A blower control unit of an automotive air conditioning system according to.

(Operation) In the present invention thus configured, when abnormal current flows through the resistance and abnormal heat is generated, such as when the motor is locked, the solder forming the thermal fuse is While melting due to heat generation, the resistance is immediately absorbed by the opposing end of the resistance in the conduction breaker, and the resistance is immediately separated. As a result, the power supply to the fan motor is immediately cut off.

The solder is a general term for low temperature molten metals and alloys, and has a broader meaning than solder generally called.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic explanatory view showing an embodiment of the first present invention, FIG. 2 is a sectional view of an essential part of the same embodiment, and members shown in FIGS. 7 (a) and 7 (b). The same members as those in are denoted by the same reference numerals.

In the blower control device 1, as shown in FIG.
A fan motor M for driving a fan f of a blower is connected to a base line L connected to one end of a battery B of a vehicle via a current fuse F ₃ of an automobile air conditioner. Further, a fan switch SW is connected to the fan motor M via a flat resistance 2 in which resistance R (a collective term of unit resistances R _{1 to} R ₃ ) is formed, whereby the drive circuit Mc of the fan motor M is connected. Are formed.

In the drive circuit Mc of the fan motor M, a terminal T (unit terminal T ₁ that determines the rotation speed of the fan motor M by sliding the mover K of the fan switch SW).
To T ₄ ) is appropriately selected to change the rotation speed of the fan motor M in multiple stages. In the case of the present embodiment, this terminal T is a unit terminal T ₁ for high speed (HI), a unit terminal T ₂ for medium and high speed (MH), a unit terminal T ₃ for medium and low speed (ML),
It is composed of four terminals, a unit terminal T ₄ for low speed (LO).

In the flat resistance 2, a plurality of unit resistances R _{1 to} R ₃ are printed on the flat electrically insulating substrate 3, and the unit resistances R _{1 to} R ₃ are electrically connected in series to reduce the resistance R. A circuit is formed and the unit resistances R _{1 to} R ₃ are electrically connected to the unit terminals T _{1 to} T ₄ described above by soldering or the like.

Here, as shown in FIG. 2, the substrate 3 is composed of a so-called enamel plate in which heat resistant insulating layers 9 and 9 are electrically glazed on the upper and lower surfaces of an iron plate 8 serving as a base. The circuit of resistance R described above is formed by printing, and the surface thereof is covered with a glass heat resistant insulating layer 10 such as glass for the purpose of preventing dust adhesion.

The resistance R is composed of a unit resistance R ₁ , a unit resistance R ₂ , and a unit resistance R ₃ . The hitting to form a circuit of this resistance R, such that the resistance value of each unit resistance R ₁ to R ₃ becomes a predetermined value, made of silver-palladium alloy constituting the unit resistance R ₁ to R ₃ groups This is achieved by printing the material on the substrate 3 in a predetermined pattern and then fixing it by baking.

Here, the unit resistance R ₂ is smaller than the cross-sectional area of the resistance member constituting the unit resistance R ₁ , and the unit resistance R ₃ is smaller than the cross-sectional area of the resistance member constituting the other unit resistances R ₁ and R _2. It is small and short in length. Thereby, the degree of freedom in considering the printing space and the layout of the printing pattern of the circuit of the resistance R on the substrate 3 is improved, and the flat resistance 2 as a whole is downsized.

Flat Resistance 2 in this embodiment, the thermal fuse F ₁ is disposed in the unit resistance R ₁ moiety described previously, the thermal fuse F ₁ is the a conducting cut-off portion 4 solder 5, and configuration substrate resistance R As compared with silver-palladium alloy, it is composed of silver layers 6 and 6 which are material layers having good wettability to molten solder.

Conducting blocking part 4, by missing the printing of a portion of the unit resistance R _1, is intended to form part of the unit resistance R ₁ are electrically disconnected, prior to coating the glass heat insulating layer 10 In the state, the heat-resistant insulating layer 9
Is exposed or a through hole is formed as shown in FIG. 7 (a).

As described above, the continuity cutoff unit 4 has a unit resistance.
Since the printing of a part of R ₁ is omitted, the unit resistance R ₁ is formed with two end portions Ra and Rb. Particularly, in the present embodiment, both end portions Ra and Rb are formed.
The silver layers 6 and 6 are formed by baking and fixing silver on Ra and Rb.

Here, the reason why the silver layers are formed on both ends Ra and Rb of the unit resistance R ₁ is that the solder 5 which will be described later is bridged to both ends Ra and Rb.
This is because when the solder 5 is melted, the solder 5 is pulled to both ends Ra and Rb through the silver layers 6 and 6 so as to realize fusing with excellent responsiveness. Therefore, a layer made of a substance rich in so-called “wettability” with the solder 5 is formed at both ends Ra and Rb of the unit resistance R ₁ .

In this embodiment, the silver layers 6 and 6 are formed on both ends Ra and Rb, but as described above, any material having a high wettability to the solder 5 can be appropriately selected.

Further, as shown in FIG. 2, after the silver layers 6 and 6 are formed on both ends Ra and Rb of the unit resistance R ₁ as described above, the solder 5 that bridges the silver layers 6 and 6 is provided.

In addition, a support plate is provided on the outer periphery of the flat resistance 2.
The support plate 13 is formed with a through hole (not shown) (see FIG. 1). Then, in a state where the terminal T is projected from the fan scroll to the outside in the fan scroll of the automobile air conditioner, a screw is inserted into the through hole to form a top plate, a bell mouth, a bottom plate or a side wall of the fan scroll. It can be installed.

Here, in order to ensure that the thermal fuse F ₂ is blown, the thermal fuse F ₂ is attached to a unit resistance R ₁ which is always energized except in the HI state, that is, when the circuit of the resistance R is energized.

Furthermore, the thermal fuse F ₂ configured similarly to the thermal fuse F ₁ to a unit resistance R ₃ spaced relative to the unit resistance R ₁ provided, resistance on the substrate 3 R
It is designed to improve responsiveness to abnormal heat generation and ensure safety.

Next, the operation will be described.

The blower control device 1 of the present embodiment configured as described above appropriately changes the total resistance value by sliding the mover K of the fan switch SW shown in FIG. 1 to rotate the motor HI, MH. , ML, LO can be switched to four stages, for example,
The case where the mover K selects the LO position of the alternate long and short dash line position will be described.

When the fan switch SW is turned on and the mover K is connected to the LO terminal T ₄ , the current from the battery B is the current fuse F ₃ ,
It flows to the HI terminal T ₁ via the fan motor M.

This current is further applied to the HI terminal T ₁ → thermal fuse F ₂ → unit resistance R ₁ → unit resistance R ₂ → thermal fuse F ₂ →
Unit resistance R ₃ → LO terminal T ₄ → mover K flows.

In this case, when a current flows through the unit resistances R _{1 to} R ₃ , the resistance R generates heat, and this heat is generated by the substrate 3
Be transmitted to.

However, the resistance R is widely arranged over the entire substrate 3, and since this substrate is so-called flat resistance that is flat and has a large area, the contact area with air is large and the transmitted heat is The air passing through the air passage of the fan scroll quickly dissipates heat.

On the other hand, if when doing the control described above, when the fan motor M and locks abnormally rotating for some reason, abnormal current flows through the unit resistance R ₁ to R _3, the unit resistance R ₁ ~ The temperature of R ₃ becomes extremely high. In this case, the heat generated from the resistance R is not only dissipated to the outside through the substrate 3, but also the thermal fuse F ₁ attached to the unit resistance R ₁ (R ₃ ).
It will be immediately transmitted to (F ₂ ) (see Fig. 3 (a)).

In this case, when the abnormal heat of the resistance R is transmitted, the temperature fuse F ₁ (F ₂ ) is melted, and the solder 5 in the melted state is resisted by the resistance R facing the cutoff portion 4.
It is absorbed by the silver layers 6 and 6 provided at both ends Ra and Rb of ₁ (R ₃ ). As a result, the solder 5 has a unit resistance R
Both ends Ra, Rb of ₁ (R ₃ ), that is, pulled in the direction of separation (see FIG. 3 (b)).

Therefore, the solder 5 in a molten state is quickly absorbed and pulled by the silver layers 6 and 6 and immediately separated into two, and the resistance R circuit is electrically cut off, and the fan motor The power supply to M is stopped (see FIG. 3 (c)).

That is, when the resistance R generates abnormal heat,
The thermal fuse F ₁ (F ₂ ) will blow immediately.

The present invention is not limited to the above-described embodiments, and various modifications can be considered.

FIG. 4 is an explanatory view of essential parts of a second embodiment of the present invention, and FIG. 5 is an explanatory view of essential parts of a third embodiment of the present invention.

In the second embodiment shown in FIG. 4, the silver layer 6 is formed on one end Ra of the resistance R facing the conduction breaker 4.
To form. Even in this case, the same effect as that of the first embodiment can be obtained.

Further, in the third embodiment shown in FIG. 5, both ends Ra and Rb of the resistance R opposing each other in the conduction breaker 4 are similarly provided.
The silver layer 6 formed on one end Ra of the silver layers 6, 6 formed on the other side has a larger surface area than the silver layer 6 formed on the other end Rb.

In this way, by making the tensile force of the solder 5 in the molten state different between the both ends Ra, Rb of the resistance R, the responsiveness of the melting of the solder 5 can be improved.

In each of the above-mentioned embodiments, the silver layer 6 is connected to the resistance R
It is constructed by connecting to the ends Ra, Rb of the
It may be formed by coating a and Rb.

In the above-mentioned embodiments, the resistance R is silver.
Made of palladium alloy, the end of resistance R Ra, Rb
According to the present invention, from the relationship of the interfacial tension between the molten solder and the resistance base material, and between the molten solder and the material layer with good wettability, Since the material having good wettability is to be determined, the difference in the resistance base material, the difference in the solder material,
Needless to say, various types of material layers having good wettability are selected.

Further, FIG. 6 is an embodiment showing a second device of the present application. In this embodiment, both ends Ra and Rb of the resistance R facing each other in the conduction breaker 4 are formed by the screen printing method.

That is, use a screen of 100 mesh or less, or use a special screen with a thick wire of 0,15 mm and a smaller pitch, and both ends Ra, Rb have fine irregularities (for example, irregularities). Pitch 0,01 ~ 0,2
mm, depth 5 to 20 μm).

Incidentally, the manufacturing method is not limited to this method, after forming both ends Ra, Rb by a normal screen printing method,
Fine ruggedness can be formed by blasting or hairline processing.

In the second invention, the molten solder is efficiently pulled to the both ends Ra and Rb by utilizing the capillary phenomenon of the fine irregularities of the both ends Ra and Rb. Even so, the same effect as that of the first invention is exhibited.

[Advantages of the Invention] As described above, according to the present invention, when abnormal heat generation occurs in the resistance, the thermal fuse is immediately blown to cut off the power supply to the fan motor. As a result, it is possible to prevent various problems due to abnormal heat generation of the resistance.

[Brief description of drawings]

FIG. 1 is a schematic explanatory view showing an embodiment of the first invention, and FIG.
The figure is a sectional view of an essential part of the embodiment, and FIGS. 3 (a), (b),
FIG. 4C is a diagram for explaining a melting action state of the temperature fuse at the time of abnormal heating of the resistance of the embodiment, FIGS.
FIG. 5 is an explanatory view of essential parts showing another embodiment of the present invention, FIG. 6 is an explanatory view of essential parts showing an embodiment of the second invention, and FIGS. 7 (a) and 7 (b) are conventional drawings. It is a principal part explanatory view of the ventilation control apparatus of the air conditioning apparatus for motor vehicles. DESCRIPTION OF SYMBOLS 1 ... Blower control device, 2 ... Flat resistance, 3 ... Electrically insulating substrate, 4 ... Conduction interruption part, 5 ... Solder, 6 ... Silver layer (material layer with good wettability), 7a, 7b ... End part, M … Fan motor, F ₁ , F ₂ … Thermal fuse, R… Resistance, R ₁
~ R ₃ ... Unit resistance.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Creator Okuyama et al. 1-5-1 Kiba, Koto-ku, Tokyo Fujikura Electric Wire Co., Ltd. (72) Takao Suzuki 1-5-1 Kiba, Koto-ku, Tokyo Fujikura Electric wire company (72) Inventor Masanori Ito 1-5-1, Kiba, Koto-ku, Tokyo Fujikura Electric Line Co., Ltd. (72) Kenichi Uruga 1-5-1, Kiba, Koto-ku, Tokyo Fujikura Den Line Co., Ltd.

Claims (2)

[Scope of utility model registration request] 1. A total resistance value of a resistance (R) circuit in which a plurality of resistances (R) are printed on a flat electrically insulating substrate (3) and the resistances (R) are electrically connected in series. The voltage applied to the fan motor (M) of the automobile air conditioner is changed to control the rotation speed of the motor (M) in multiple stages, and the resistance (R) is abnormally heated. in blowing control apparatus for an automobile air conditioning system comprising includes a temperature fuse to cut off the power supply of the to the motor (M) and blown (F _1, F ₂₎ by the temperature fuse (F _1, F ₂₎ A resistance cutoff section (4) for cutting off the resistance (R) circuit, and a solder (5) bridging the resistance cutoff section (4) for connecting the resistance (R) circuit. In the conduction block (4) At least one of the opposite ends (Ra, Rb) of the resistance (R) is provided with a material layer (6) having better wettability than the resistance (R) base material, and the resistance (R) The solder (5) that is in a molten state due to abnormal heat generation of (R) easily
A blower control device for an automobile air conditioner, characterized in that it is pulled by b). 2. A total resistance value of a resistance (R) circuit in which a plurality of resistances (R) are printed on a flat electrically insulating substrate (3) and the resistances (R) are electrically connected in series. The voltage applied to the fan motor (M) of the automobile air conditioner is changed to control the rotation speed of the motor (M) in multiple stages, and the resistance (R) is abnormally heated. in blowing control apparatus for an automobile air conditioning system comprising includes a temperature fuse to cut off the power supply of the to the motor (M) and blown (F _1, F ₂₎ by the temperature fuse (F _1, F ₂₎ A resistance cutoff section (4) for cutting off the resistance (R) circuit, and a solder (5) bridging the resistance cutoff section (4) for connecting the resistance (R) circuit. In the conduction block (4) At least one of the opposite ends (Ra, Rb) of the resistance (R) facing each other is formed into a fine uneven shape, and a ventilation control device for an air conditioner for a vehicle.