JP2002321523A - Defrosting apparatus for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To securely prevent a frosting phenomena of the refrigerant evaporator 1 by providing, in a capillary tube 4 which is a temperature sensor, an insertion amount adjustment guide 9 which is a stopper for a positioning to a refrigerant tube 14 or a cooling fin 15 of a refrigerant evaporator 1. SOLUTION: The length from the insertion amount adjustment guide 9 to a tip end 41 of the capillary tube 4 inserted into the refrigerant evaporator 1 is used as a length necessary for appropriately detecting the temperature of the refrigerant evaporator 1. As a result, in a manufacture step of a cooling unit of an air conditioning apparatus for automobile, when the capillary tube 4 is inserted between the cooling fins 15 of the refrigerant evaporator 1 so that the capillary tube 4 is inserted into the refrigerant evaporator 1 until the insertion amount adjustment guide 9 has a contact with a lee-side end and an end on the side of a low temperature region of the refrigerant tube 14 or the cooling fin 15, then the insertion amount of the capillary tube 4 is maintained at a length necessary for appropriately sensing the temperature of the refrigerant evaporator 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle defroster for removing frost adhering to a refrigerant evaporator of a refrigeration cycle of a vehicle air conditioner, and more particularly to a refrigerant tube or a refrigerant tube inserted into the refrigerant evaporator. The present invention relates to a vehicle defrosting apparatus including a mechanical thermostat capable of maintaining a constant insertion amount of a capillary tube for detecting a temperature of a refrigerant evaporator in contact with a cooling fin.

[0002]

2. Description of the Related Art In a refrigerant evaporator of a refrigeration cycle of a vehicle air conditioner, warm air hits a cooling fin of the refrigerant evaporator, and when cooled, water in the air is condensed and water droplets adhere to the cooling fin. At this time, if the temperature of the cooling fins is cooled to, for example, 0 ° C. or lower, the attached water droplets freeze or become frost (frost phenomenon).
When such a frost phenomenon occurs in the refrigerant evaporator, the heat exchange efficiency (heat absorption efficiency, cooling efficiency) in the refrigerant evaporator decreases, and sufficient cooling capacity cannot be obtained.

In order to prevent the frost phenomenon of the refrigerant evaporator, a capillary tube for detecting the temperature of the refrigerant evaporator is provided. A mechanical thermostat having a box-shaped main body for outputting an electric signal for stopping the operation of the refrigeration cycle by turning off the electromagnetic clutch is mounted.

[0004] This mechanical thermostat is provided with a temperature sensing part (heat sensing part) in a refrigerant tube or a cooling fin of a refrigerant evaporator.
When the pressure of the medium sealed in the capillary tube changes according to the temperature change of the refrigerant evaporator, the contact built in the main body becomes O.
A structure in which N-OFF is repeated is adopted (for example, Japanese Utility Model Laid-Open No. 49-5136).

Here, in order to normally generate the pressure change corresponding to the above-mentioned temperature change, the temperature of the refrigerant evaporator in the low temperature region is smaller than the surface area of the capillary tube required for properly sensing the temperature of the refrigerant evaporator. It is known that the surface area of the capillary tube in contact with the surface must be increased.

[0006]

However, Japanese Utility Model Laid-Open No. 49-5136 described above discloses that a capillary tube is inserted between cooling fins of a refrigerant evaporator. There is no statement as to whether the plate is larger or smaller than the spacing between the refrigerant tubes of the refrigerant evaporator. That is, there is no description of the positioning means for keeping the length from the tip of the capillary tube to the wind speed suppressing plate at a length necessary for properly detecting the temperature of the refrigerant evaporator.

Therefore, as shown in FIG. 9, when the capillary tube 102 is inserted between the two refrigerant tubes 101 adjacent to the refrigerant evaporator so as to contact the cooling fins 103, the capillary tube 102 It is not always possible to insert it to the length necessary to properly detect the temperature of the evaporator. That is, the surface area of the capillary tube in contact with the low-temperature region of the refrigerant evaporator cannot be larger than the surface area of the capillary tube required for properly sensing the temperature of the refrigerant evaporator. For this reason, there is a possibility that temperature detection failure may occur due to insufficient insertion of the capillary tube 102, and there is a problem that the frost phenomenon of the refrigerant evaporator occurs as described above.

[0008]

SUMMARY OF THE INVENTION It is an object of the present invention to reliably prevent a frost phenomenon of a refrigerant evaporator by providing a stopper for a refrigerant tube or a cooling fin of the refrigerant evaporator in a capillary tube as a temperature sensing part. Further, when inserting the capillary tube into the refrigerant evaporator, the stopper is inserted until the stopper comes into contact with the leeward side end or the low temperature region side end of the refrigerant evaporator, thereby reliably preventing the frost phenomenon of the refrigerant evaporator. Aim.

[0009]

According to the first aspect of the present invention, a stopper is provided at a predetermined position from the distal end portion of the capillary tube of the mechanical thermostat to the main body, so that the inside of the refrigerant evaporator is provided. The insertion amount of the capillary tube can be kept constant. According to the second aspect of the present invention, the length from the stopper to the tip of the capillary tube inserted into the refrigerant evaporator is set to the length necessary for properly detecting the temperature of the refrigerant evaporator. By doing so, the insertion amount of the capillary tube into the refrigerant evaporator can be kept constant. As a result, when the capillary tube is inserted into the refrigerant evaporator in the manufacturing process of the vehicle defroster, temperature detection failure due to insufficient insertion of the capillary tube does not occur, and the frost phenomenon of the refrigerant evaporator is reliably prevented. can do.

According to the third aspect of the present invention, the stopper is integrally formed with the capillary tube of the mechanical thermostat, so that it is not necessary to attach the stopper, which is a separate component, to the capillary tube in the process of manufacturing the vehicle defroster. Absent. Thereby, the number of parts of the vehicle defroster can be reduced, and the assembling workability can be improved, so that the manufacturing cost of the vehicle defroster can be reduced.

According to the fourth aspect of the present invention, the capillary tube is provided with a plurality of turn portions which are bent and formed into a substantially U shape at least twice. The stopper is formed integrally with at least one of the plurality of turns, and is positioned by being locked to a leeward end or a low-temperature region end of the refrigerant evaporator. According to the fifth aspect of the present invention, the capillary tube is provided so as to be branched into at least two parts in the middle. The stopper is integrally formed in the middle of the capillary tube, and is locked and positioned at the leeward side end or the low temperature region side end of the refrigerant evaporator. Accordingly, the surface area of the capillary tube in contact with the low-temperature region of the refrigerant evaporator can be increased as compared with the capillary tube having only one turn portion, so that the frost phenomenon of the refrigerant evaporator can be reliably prevented.

According to the sixth aspect of the present invention, the refrigerant evaporator has a temperature difference between the near side and the far side in the mounting direction of the capillary tube, and the near side in the mounting direction of the capillary tube has: A low-temperature region where the temperature is lower than the depth in the mounting direction of the capillary tube is provided, and a high-temperature region where the temperature is higher than the near side in the mounting direction of the capillary tube is provided in the depth in the mounting direction of the capillary tube. ing. Thereby, the surface area of the capillary tube in contact with the low temperature region of the refrigerant evaporator can be made larger than the surface area of the capillary tube required for properly sensing the temperature of the refrigerant evaporator. As a result, a pressure change corresponding to a temperature change of the medium sealed in the capillary tube can be normally generated, so that the frost phenomenon of the refrigerant evaporator can be reliably prevented.

According to the seventh aspect of the present invention, the length of the stopper in the width direction is set to be greater than the distance between two adjacent refrigerant flow pipes, so that the capillary tube is formed. A function as a stopper for positioning can be provided. As a result, when the capillary tube is inserted into the refrigerant evaporator in the manufacturing process of the vehicle defroster, temperature detection failure due to insufficient insertion of the capillary tube does not occur, and the frost phenomenon of the refrigerant evaporator is reliably prevented. can do.

According to the eighth aspect of the present invention, the stopper is locked and positioned at the leeward end or the low temperature region end of at least one of the plurality of refrigerant flow pipes. I have. As a result, the surface area of the capillary tube in contact with the low-temperature region of the refrigerant evaporator can be increased,
The frost phenomenon of the refrigerant evaporator can be reliably prevented.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described based on embodiments with reference to the drawings. [Configuration of First Embodiment] FIGS. 1 to 5 show a first embodiment of the present invention.
FIG. 1 is a view showing an embodiment in which an insertion amount adjusting guide is attached to a capillary tube, FIG. 2 is a view showing a refrigerant evaporator and an expansion valve of a refrigeration cycle, and FIG.
FIG. 3 is a diagram showing a main part of a refrigerant evaporator of a refrigeration cycle.

A refrigeration cycle used in an air conditioner for a vehicle such as a car air conditioner of the present embodiment includes a refrigerant evaporator 1 for exchanging heat between a refrigerant and air to evaporate and evaporate the refrigerant. Also, the expansion valve 2 is installed on the upstream side in the flow direction of the refrigerant. The refrigerant evaporator 1, the expansion valve 2, and the capillary tube 4 of the mechanical thermostat 3 for preventing frost of the refrigerant evaporator 1 are arranged in an air-conditioning duct (not shown). To form a vehicle defroster. For this reason, the high-pressure pipe 5 is fixedly fastened to the inlet of the expansion valve 2, and the low-pressure pipe 6 is fixedly fixed to the outlet of the expansion valve 2.

Further, a block 11 holding an inlet pipe 22 and an outlet pipe 28 integrally formed with the refrigerant evaporator 1.
The cooling unit of the refrigeration cycle is assembled by tightening and fixing the joint 12 holding the two low-pressure pipes 6 and 7 using bolts 13. Here, the refrigeration cycle includes a refrigerant compressor, a refrigerant condenser, a receiver, an expansion valve 2, a refrigerant evaporator 1, a refrigerant pipe connecting these components in a ring, and the like. The refrigerant compressor is configured to be rotationally driven by the engine via an electromagnetic clutch. The electromagnetic clutch interrupts the rotational power transmitted from the engine to the refrigerant compressor.

The refrigerant evaporator 1 is disposed so as to entirely cover the inside of the unit case of the cooling unit.
An evaporator that evaporates and evaporates the refrigerant by exchanging heat between the refrigerant and the air performs an air cooling function of cooling air passing through the evaporator and an air dehumidifying function of dehumidifying air passing through the self. In the refrigerant evaporator 1, a flat refrigerant flow pipe (hereinafter, referred to as a refrigerant tube) 14 having a pair of tank parts at one end and a refrigerant evaporation passage at another part and cooling fins 15 are alternately arranged in the width direction. It is a laminated heat exchanger (evaporator) formed by laminating a plurality of layers.

Here, the cooling fins 15 are corrugated fins formed in a corrugated shape, and have a large number of louvers 16 formed therein. A mechanical thermostat 3 described later is inserted into an air passage 17 surrounded by cooling fins 15 on the downstream side in the air flow direction and on the upstream side in the refrigerant flow direction. In the refrigerant evaporator 1, an inlet pipe 22 for flowing the refrigerant into the inside and an outlet pipe 28 for flowing the refrigerant from the inside are arranged at substantially the center of the plurality of refrigerant tubes 14 in the laminating direction so as to be adjacent to each other. I have. Then, in the refrigerant evaporator 1, as shown in FIGS.
Inlet pipe 22 → inlet tank 23 → a plurality of substantially U-shaped inlet side refrigerant evaporation passages 24 → intermediate tank 25 → a plurality of substantially U-shaped outlet side refrigerant evaporation paths 26 → outlet tank 27 → outlet pipe 28 Coolant flows.

In the refrigerant evaporator 1, the refrigerant in the gas-liquid two-phase state exchanges heat with air in the inlet-side refrigerant evaporating passage 24 to largely evaporate and evaporate by adjusting the amount of refrigerant by the expansion valve 2. The evaporation of the refrigerant is completed at the outlet side of the side refrigerant evaporation passage 26. For this reason, the surface temperature of the refrigerant evaporator 1 is lower in the inlet-side refrigerant evaporation passage 24 than in the outlet-side refrigerant evaporation passage 26. In addition, the surface temperature of the inlet-side refrigerant evaporation passage 24 is lower on the inlet side than on the outlet side. Therefore,
In order to reliably prevent frost, a capillary tube 4 which is a temperature sensing part of a mechanical thermostat 3 described later is used.
Is desirably inserted so as to have a large surface area in contact with the refrigerant tubes 14 or the cooling fins 15 in the low temperature region (low temperature region) on the inlet side of the inlet side refrigerant evaporation passage 24.

A temperature sensing tube 32 is attached to the expansion valve 2 via a long and extended capillary tube 31. The temperature-sensitive cylinder 32 is closely attached to the outer peripheral surface of the low-pressure pipe 7 for guiding the refrigerant flowing out of the outlet pipe 28 of the refrigerant evaporator 1 to the refrigerant compressor by using a clamp 33. Inside the temperature-sensitive cylinder 32, a temperature-sensitive chamber in which a gas refrigerant and a large number of adsorbents (for example, activated carbon) are stored is formed. The internal pressure of the temperature-sensitive cylinder 32 varies according to the installation temperature of the temperature-sensitive cylinder 32, that is, the temperature of the refrigerant flowing out of the refrigerant evaporator 1. Specifically, when the temperature of the refrigerant decreases, the gas refrigerant is adsorbed by the adsorbent, and the internal pressure of the temperature-sensitive cylinder 32 decreases. Conversely, when the temperature of the refrigerant increases, the gas refrigerant separates from the adsorbent, and the internal pressure of the temperature-sensitive cylinder 32 increases.

Next, the mechanical thermostat of this embodiment will be described with reference to FIGS. Here, FIG. 5 is a diagram showing the entire configuration of the mechanical thermostat. The mechanical thermostat 3 includes a capillary tube 4 that is a temperature sensing unit (heat sensing unit) that detects the temperature of the refrigerant evaporator 1, a box-type main body unit 8 that is a signal generator that outputs an electric signal, and a refrigerant evaporator. An insertion amount adjustment guide 9 is a stopper for positioning the one refrigerant tube 14 or the cooling fin 15 with respect to the downwind side end and the low temperature region side end.

The capillary tube 4 is made of a thin flow tube (external diameter of φ2 mm or less) made of a metal material such as copper having excellent heat conductivity.
A medium (for example, a liquid or a gas) that converts a temperature change into a pressure change is sealed in a pressure guiding path from the distal end portion 41 to the main body 8. The capillary tube 4 is inserted into the air passage 17 between the cooling fins 15 in the low temperature region on the right side of the drawing in the laminating direction of the refrigerant tubes 14 in FIG. Have been.

In the present embodiment, the temperature of the refrigerant evaporator 1 is lower (the temperature is higher than that of the higher temperature region) of the refrigerant evaporator 1 than the capillary tube surface area required for the capillary tube 4 to properly detect the temperature of the refrigerant evaporator 1. Low area: downwind,
The insertion amount of the capillary tube 4 into the refrigerant evaporator 1 is set so that the surface area of the capillary tube in contact with the upstream side in the flow direction of the refrigerant increases.

In the middle of the portion of the capillary tube 4 that is inserted into the refrigerant evaporator 1, a turn portion (bent portion) 42 that is bent in an inverted U-shape is provided. The turn portion 42 is provided in a region where the temperature of the refrigerant evaporator 1 is higher than that in a region where the temperature is low.
The two straight portions on both sides are provided in a region where the temperature of the refrigerant evaporator 1 is lower than a region where the temperature is high.

The main body 8 is held and fixed in an air-conditioning duct, particularly in a unit case of a cooling unit. When the pressure of the medium sealed in the capillary tube 4 changes, a built-in contact (not shown) is turned on. It is configured to repeat -OFF. In the present embodiment, when the temperature of the refrigerant evaporator 1 rises to, for example, 4 ° C. or higher, the contact built in the main body 8 turns on. Further, when the temperature of the refrigerant evaporator 1 drops to, for example, 3 ° C. or less, the contact built in the main body 8 is turned off. Thereby, in order to prevent frost of the refrigerant evaporator 1, the electromagnetic clutch of the refrigerant compressor is turned off.
F.

When inserting the capillary tube 4 into the refrigerant evaporator 1, the insertion amount adjusting guide 9
Of the refrigerant tube 14 or the cooling fin 15 on the leeward side end and the low temperature region side end. That is, the insertion amount adjustment guide 9 is provided so as to contact the leeward side end and the low temperature region side end of the refrigerant tube 14 or the cooling fin 15 of the refrigerant evaporator 1. Therefore, the length from the insertion amount adjustment guide 9 to the distal end portion 41 of the capillary tube 4 inserted into the refrigerant evaporator 1 is a length necessary for properly detecting the temperature of the refrigerant evaporator 1 (for example, 100 mm). ).

[Operation of First Embodiment] Next, the operation of the automotive air conditioner of the present embodiment will be briefly described with reference to FIGS.

The air sucked into the air conditioning duct with the rotation of the indoor blower (not shown) of the automotive air conditioner flows into the unit case of the cooling unit,
When passing through many air passages 17 surrounded by the cooling fins 15 of the refrigerant evaporator 1, the refrigerant evaporates and exchanges heat with the refrigerant flowing in the refrigerant tube 14 to cool the interior of the automobile. At this time, when the temperature of the refrigerant evaporator 1 drops to, for example, 3 ° C. or less, the liquid pressure sealed in the capillary tube 4 which is a temperature-sensitive portion changes, so that the contact built in the main body 8 is turned off. .

Then, the electromagnetic clutch of the refrigerant compressor is turned on.
F, the supercooling of the refrigerant evaporator 1 is suppressed, and the temperature of the refrigerant evaporator 1 rises, so that frost is formed on the surfaces of the refrigerant tubes 14 and the cooling fins 15 of the refrigerant evaporator 1,
Alternatively, frost adhering to the surfaces of the refrigerant tubes 14 and the cooling fins 15 can be removed. Conversely, when the temperature of the refrigerant evaporator 1 rises to, for example, 4 ° C. or higher, the contact pressure built in the main body 8 is turned on by a change in the liquid pressure sealed in the capillary tube 4 which is a temperature sensing part. . Then, the electromagnetic clutch of the refrigerant compressor is turned on, and the interior of the vehicle is cooled.

[Effects of the First Embodiment] In the present embodiment,
As shown in FIG. 1, the distal end portion 41 of the capillary tube 4 inserted into the refrigerant evaporator 1 from the insertion amount adjustment guide 9.
The length up to is required for properly detecting the temperature of the refrigerant evaporator 1. Accordingly, when the capillary tube 4 is inserted between the cooling fins 15 of the refrigerant evaporator 1 in the manufacturing process of the cooling unit of the automotive air conditioner, the insertion amount adjustment guide 9 is moved to the leeward side of the refrigerant tube 14 or the cooling fin 15 When the capillary tube 4 is inserted into the refrigerant evaporator 1 until it comes into contact with the end and the low-temperature region side end, the insertion amount of the capillary tube 4 is reduced to a length necessary for properly sensing the temperature of the refrigerant evaporator 1. Will be kept.

Thus, the insertion amount of the capillary tube 4 into the refrigerant evaporator 1 can always be kept constant, so that the capillary tube 4 is inserted into the refrigerant evaporator 1 in the process of manufacturing the cooling unit of the automotive air conditioner. When inserting the capillary tube, it is possible to prevent temperature detection failure due to insufficient insertion of the capillary tube 4. Therefore, frost does not occur on the surface of the refrigerant tube 14 or the cooling fins 15 of the refrigerant evaporator 1, and the frost phenomenon of the refrigerant evaporator 1 can be reliably prevented.

[Second Embodiment] FIGS. 6A and 6B show a second embodiment of the present invention, and FIGS. 6A and 6B show an example in which a stopper is integrated with a capillary tube. .

In this embodiment, as shown in FIGS. 6A and 6B, a stopper 10 for positioning the refrigerant evaporator 1 with respect to the refrigerant tube 14 or the cooling fins 15 is used.
Is integrally formed with the capillary tube 4. Specifically, as shown in FIG. 5 (a), the stopper 10 is formed by bending the middle of the capillary tube 4 into a U-shape, or as shown in FIG. 5 (b).
In the middle of the process, a stopper 10 that protrudes so as to be larger than the interval between two adjacent refrigerant tubes 14 is formed. With this, the same effect as in the first embodiment can be obtained. As a ripple effect of the type in which the stopper 10 is integrally formed with the capillary tube 4 of this embodiment, as in the first embodiment, the capillary tube 4
It is not necessary to assemble the insertion amount adjustment guide 9 which is a separate part, and the assembling workability can be improved, so that the manufacturing cost can be reduced.

Third Embodiment FIG. 7 shows a third embodiment of the present invention. FIGS. 7A and 7B show an example in which a capillary tube is branched into a plurality of parts to form a stopper. FIG.

As shown in FIGS. 7 (a) and 7 (b), the capillary tube 4 of this embodiment is of a type in which the capillary tube 4 is branched into a plurality of parts and the stoppers 10 are integrally formed at their roots. . Specifically, as shown in FIG. 7A, the distal ends 51 to 5 of the capillary tube 4 are
The stopper 10 is composed of two straight portions protruding on both sides from the substantially cross-shaped branch portion 54 by branching from the 3 to the branch portion 54 in a branch shape, as shown in FIG. 6B. To
From the distal end portions 61 and 62 of the capillary tube 4 to the branch portion 6
3 is branched into two in a branch shape, and a substantially Y-shaped branch portion 6 is formed.
3 constitutes the stopper 10.

The linear portion from the three end portions 51 to 53 to the stopper 10 of the capillary tube 4 shown in FIG. 7A has a lower temperature region (lower temperature region) than the higher temperature region of the refrigerant evaporator 1. 7B), and the straight line portion from the two end portions 61, 62 of the capillary tube 4 shown in FIG. 7B to the turn portions 64, 65 bent in an inverted U shape is the refrigerant evaporator 1 Are arranged in a region where the temperature is lower (low temperature region) than in a region where the temperature is high, and the inverted U-shaped turn portion 6 is provided.
The stoppers 4 and 65 are inserted into a region where the temperature of the refrigerant evaporator 1 is high (high-temperature region).
The straight portion up to 0 is arranged in a region where the temperature of the refrigerant evaporator 1 is low (low temperature region).

[Fourth Embodiment] FIG. 8 shows a fourth embodiment of the present invention. FIG. 8 is a diagram showing an example in which a stopper is formed by bending a capillary tube into a W shape.

In the present embodiment, instead of the insertion amount adjusting guide 9, as shown in FIG. 8, the shape of the capillary tube 4 is a plurality of bent shapes such as an S shape, a W shape, or the like. In addition, one of the capillary tubes 4 shown in FIG.
The straight portion from the two tip portions 71 to the inverted U-shaped bent portion 72 is arranged in a region (low temperature region) where the temperature of the refrigerant evaporator 1 is lower than the region where the temperature is high, and has an inverted U-shape. The turn portion 72 is inserted into a region where the temperature of the refrigerant evaporator 1 is high (high temperature region).

The straight portion from the inverted U-shaped turn portion 72 to the U-shaped turn portion 73 (stopper 10) is disposed in a region where the temperature of the refrigerant evaporator 1 is low (low temperature region). The straight portion from the U-shaped turn portion 73 to the inverted U-shaped turn portion 74 is disposed in a region (low temperature region) where the temperature of the refrigerant evaporator 1 is low, and the inverted U-shaped turn portion 74 is 1 is inserted into the high temperature region (high temperature region), and the straight portion from the inverted U-shaped turn portion 74 to the base end portion 75 is arranged in the low temperature region (low temperature region) of the refrigerant evaporator 1. I have. The U-shaped turn 73 constitutes a stopper 10 for positioning the refrigerant evaporator 1 with respect to the refrigerant tube 14 or the cooling fins 15.

Therefore, when the capillary tube 4 is inserted between the cooling fins 15 of the refrigerant evaporator 1 in the manufacturing process of the cooling unit of the automotive air conditioner, the turn portion 73 (stopper 10) of the capillary tube 4 14 or the cooling fins 15 until the capillary tubes 4
Is inserted into the refrigerant evaporator 1, and a plurality of bent shapes such as an S-shape, a W-shape, etc., from the distal end portion 71 to the base end portion 75 of the capillary tube 4 are connected to the refrigerant tube 14 or the cooling fin 15. By making contact, the insertion amount of the capillary tube 4 can always be maintained at a value equal to or longer than a length necessary for properly sensing the temperature of the refrigerant evaporator 1.

The ripple effect at this time is, as shown in FIG. 8, the surface of the capillary tube in contact with a region where the temperature of the refrigerant evaporator 1 is lower than that of the simple U-shape (low temperature region). Since the area is increased, the refrigerant evaporator 1 having a small width, the refrigerant evaporator 1 having a large temperature difference on the upstream side (windward side) in the air flow direction, and the downstream side (leeward side) in the air flow direction, etc. The capillary tube shape is optimal for the refrigerant evaporator 1 in which the width of the low temperature region is narrow.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing an example in which an insertion amount adjustment guide is attached to a capillary tube (first embodiment).

FIG. 2 is a front view showing a refrigerant evaporator and an expansion valve of the refrigeration cycle (first embodiment).

FIG. 3 is a perspective view showing a main part of a refrigerant evaporator of the refrigeration cycle (first embodiment).

FIGS. 4A and 4B are explanatory views showing the flow direction of a refrigerant in a refrigerant evaporator (first embodiment).

FIG. 5 is a perspective view showing an overall configuration of a mechanical thermostat (first embodiment).

FIGS. 6A and 6B are explanatory views showing an example in which a stopper is integrated with a capillary tube (second embodiment).

FIGS. 7A and 7B are explanatory views showing an example in which a stopper is formed by branching a capillary tube into a plurality of tubes (third embodiment).

FIG. 8 is an explanatory view showing an example in which a stopper is formed by bending a capillary tube into a W shape (fourth embodiment).

FIG. 9 is an explanatory view showing an example of insufficient insertion of a capillary tube (prior art).

[Description of Signs] 1 Refrigerant evaporator 2 Expansion valve 3 Mechanical thermostat 4 Capillary tube 8 Main body 9 Insertion amount adjustment guide (stopper) 10 Stopper 14 Refrigerant tube (refrigerant flow tube) 15 Cooling fin 41 Tip part 64 Turn part 65 turn section 72 turn section 73 turn section 74 turn section

Claims (8)

[Claims] 1. A refrigeration cycle having a refrigerant evaporator for exchanging heat between air flowing through a unit case and a refrigerant, and b. Detecting a temperature of the refrigerant evaporator by being inserted into the refrigerant evaporator. A capillary tube, and a mechanical thermostat having a main body for outputting an electric signal so as to stop the operation of the refrigeration cycle when the temperature of the refrigerant evaporator falls below a predetermined value; and (c) the capillary tube. A defroster for a vehicle, comprising: a stopper provided at a predetermined position from a distal end of the capillary tube to the main body to maintain a constant insertion amount of the capillary tube into the refrigerant evaporator. 2. The vehicle defroster according to claim 1, wherein a length from the stopper to a tip end of the capillary tube inserted into the refrigerant evaporator adjusts a temperature of the refrigerant evaporator. A defrosting device for a vehicle, wherein the length is required to detect the vehicle. 3. The defrosting device for a vehicle according to claim 2, wherein the mechanical thermostat has the stopper integrally formed with the capillary tube. 4. The vehicle defroster according to claim 3, wherein the capillary tube is substantially U-shaped at least twice.
A plurality of turn portions bent and formed in a letter shape are provided, and the stopper is integrally formed with at least one of the plurality of turn portions, and is located on a leeward side end or a low temperature region of the refrigerant evaporator. A defroster for a vehicle, wherein the defroster is positioned by being locked to a side end. 5. The vehicle defroster according to claim 3, wherein the capillary tube is provided so as to branch off at least two or more from the middle, and the stopper is integrally formed in the middle of the capillary tube. A defroster for a vehicle, wherein the defroster is positioned by being locked to a leeward end or a low-temperature region end of the refrigerant evaporator. 6. The defroster for a vehicle according to claim 3, wherein the refrigerant evaporator has a temperature difference between a near side and a far side in a mounting direction of the capillary tube. In the near side of the mounting direction of the capillary tube, a low-temperature region having a lower temperature than the far side of the mounting direction of the capillary tube is provided, and in the far side of the mounting direction of the capillary tube, the capillary is provided. A defroster for a vehicle, wherein a high-temperature region having a higher temperature than a near side in a mounting direction of a tube is provided. 7. The vehicle defroster according to claim 1, wherein the refrigerant evaporator is formed by laminating a refrigerant flow pipe connected between a pair of tank portions in a width direction. A vehicle having a core portion formed as described above, wherein the length in the width direction of the stopper has a length in the width direction that is larger than the interval between two adjacent refrigerant flow pipes. For defrosting equipment. 8. The vehicle defroster according to claim 1, wherein the refrigerant evaporator is formed by laminating a refrigerant flow pipe connected between a pair of tank portions in a width direction. Wherein the stopper is positioned by being locked to a leeward end or a low temperature region end of at least one of the plurality of refrigerant flow pipes. Vehicle defroster.