WO2006013759A1

WO2006013759A1 - Thermostat

Info

Publication number: WO2006013759A1
Application number: PCT/JP2005/013726
Authority: WO
Inventors: Yoshihide Nakajima; Yukio Morikawa
Original assignee: Matsushita Electric Industrial Co., Ltd.
Priority date: 2004-08-02
Filing date: 2005-07-27
Publication date: 2006-02-09
Also published as: JP4158751B2; JP2006048988A; CN1993789A; CN1993789B

Abstract

A thermostat in which the end surface of a defrost lever is formed with a circular hole which is larger than the defrost pin stem but smaller than the stepped section of the defrost pin to define a clearance between the defrost pin stem and the defrost lever. Since it becomes difficult for the friction force between the defrost pin and a through-hole in a cam to act on the defrost lever engageable with the defrost pin, this thermostat has a stabilized defrost return temperature with little temperature variation.

Description

Specification

Thermostat

Technical field

The present invention relates to a thermostat that is used in a refrigerator or the like and has a defrosting function such as a pushbutton for defrosting operation.

Background art

Conventionally, a thermostat in this field has a function of removing a frost adhering to a refrigerator cooler by controlling a circuit of a cooling compressor by operating a push button. Such an example is disclosed in Japanese Utility Model Publication No. 57-6029.

FIG. 6 to FIG. 8 show the conventional thermostat. As shown in the figure, one end 2a of the lever 2 is pivotally supported so as to be able to rotate on a container frame 1 having a U-shaped box body force, and the other end is engaged with the opening / closing spring 3. Install a compression spring 5 with one end on the spring receiver 4 provided in the middle of the lever 2 so that it is opposed to the bellows 6. Provide an arm 9 for opening and closing contacts (movable contact 7, fixed contact 8) on the tip of lever 2. The other end of the compression spring 5 is supported by the adjustment lever 10. One end 10a of the adjustment lever 10 is pivotally supported so that the other end is in contact with the cam surface of the displacement cam 11 having the through hole 11a. One end portion 12a of the defrost lever 12 is pivotally supported so that it can rotate, and the other end portion has a contact portion 12b so that it can contact the lever 2! One end of a wire spring 13 for reversing the defrost lever 12 is engaged with the other end of the defrost lever 12. Insert the defrost pin 15 with the push button 14 into the cam 11. Then, the adjustment plate 16 is connected to the adjustment lever 10 and the tip of the adjustment plate 16 is brought into contact with the defrost lever 12 so as to face the defrost pin 15. Further, the defrost lever 12 is provided with a circular hole 12c and a slot 12d formed in the hole 12c. Two flange portions (15b, 15c) and a shaft portion sandwiched between both flange portions are formed at the lower end portion 15a of the differential pin 15. The shaft part sandwiched between the flanges is fitted into the slot 12d of the defrost lever 12.

[0004] The operation of the thermostat configured as described above will be described below. [0005] First, when the temperature of the temperature sensing part rises, the pressure of the gas in the capillary tube rises, causing the bellows 6 to expand. As a result, the spring receiver 4 is pushed up against the force of the compression spring 5, and the lever 2 is rotated in the direction of the arrow in FIG. 6 by the action of the force of the opening and closing spring 3, and hits a stubber (not shown). It is stopped. Along with this, the arm 9 is detached from the contact plate (not shown), the movable contact 7 comes into contact with the fixed contact 8, and an ON circuit (energized state) is formed. On the other hand, when the temperature of the temperature sensing section decreases, the bellows 6 contracts, the spring receiver 4 is lowered by the force of the compression spring 5, and the lever 2 is It rotates in the opposite direction. At the same time, the arm 9 descends and hits a contact plate (not shown) to push it down, thereby moving the movable contact 7 away from the fixed contact 8 as shown. That is, an off circuit is formed. At this time, the lever 2 is stopped by a stagger (not shown).

[0006] The above is a general force of the thermostat, which is an effect due to temperature. If the push button 14 is piled and pushed down by the force of a return spring (not shown), the defrost pin 15 is lowered, and the defrost lever 12 is lowered accordingly. Further, when the defrost pin 15 is lowered, the defrost lever 12 is rotated downward by the reversal action of the wire spring 13. Then, the contact portion 12b of the defrost lever 12 comes into contact with the lever 2, forcibly turns the lever 2 downward, and separates the contacts 7 and 8 to form an off circuit. At that time, the push button 14 is stopped at the position where it is pushed by the reversal force of the wire spring 13.

[0007] On the other hand, the contacts 7 and 8 which are turned off by the operation of the push button 14 are closed as follows.

In other words, when the temperature becomes higher than the initial temperature, the lever 2 starts to rotate upward, piled on the force of the wire spring 13. Then, due to a decrease in the downward acceleration force of the opening / closing spring 3 and the wire spring 13, the lever 2 is rapidly reversed, closing the contacts 7 and 8 and forming an ON circuit. Along with this, the defrost lever 12 is pushed back by the lever 2 and returned to its original position by the action of the wire spring 13.

However, in the above-described conventional configuration, when the contacts 7 and 8 that are turned off are energized at a high temperature, the following occurs. The lower end portion 15a of the defrost pin 15 is fixed by fitting the two flange portions (15b, 15c) and the shaft portion sandwiched between both flange portions into the groove holes 12d of the defrost lever 12. As a result, defrost lever 12 and defrost pin 15 The fixed part of the shaft rotates along an arc-shaped track with the pivoted one end 12a as a fulcrum. Similarly, the defrost pin 15 does not move vertically up and down, but moves up and down while contacting the side surface portion of the through hole 11a formed in the operation shaft of the cam 11. The sliding friction force acts in a direction that prevents the reversing force of the defrost lever 12 and at the same time hinders the reversing force of the lever 2. In other words, the temperature at which the defrost pin 15 returns to its original position and the contacts (7, 8) return from off to on is affected by the frictional force. That is, the conventional thermostat having the above configuration has a problem that the return temperature varies and may change.

[0009] Furthermore, when the flange portions (15b, 15c) of the defrost pin 15 are inserted into the defrost lever groove hole 12d, it is necessary to securely insert and engage them without rattling or displacement. For this purpose, sufficient dimensional accuracy management and dedicated jigs are necessary, and there is a problem when the man-hours required for fitting are large.

Disclosure of the invention

[0010] The present invention provides a thermostat in which a hole larger than a defrost pin shaft diameter is provided in an end surface portion of a defrost lever so that the defrost pin can be inserted in engagement between a lower end portion of the defrost pin and an end surface of the defrost lever. Even if the defrost lever performs an arc-shaped trajectory, there is a clearance between the defrost pin shaft and the defrost lever hole, so the defrost pin does not operate in the same orbit as the defrost lever. Instead, it moves vertically upward along the through hole of the cam. As a result, changes and variations in the return temperature can be suppressed without being affected by the frictional force caused by the operation.

[0011] Further, the present invention provides a thermostat in which a cap larger than the diameter of the defrost lever hole is attached to the lower end portion of the defrost pin after passing the defrost pin through the defrost lever hole. As a result, the defrost pin and the defrost lever can be easily assembled into the through-holes of the frame and the cam without using a special jig or the like that prevents the parts from being removed.

[0012] Furthermore, the present invention provides a thermostat in which a defrost pin has a lower end formed into a larger diameter than the defrost lever hole after passing the defrost pin through the defrost lever hole. As a result, the defrost pin and the defrost lever can be easily assembled into the through hole of the casing and the cam without using a special jig or the like that prevents the parts from coming off. Part Increase in the number of products An inexpensive thermostat without tl can be realized.

Brief Description of Drawings

FIG. 1 is a cross-sectional view showing a normal state of a thermostat according to an embodiment of the present invention.

2 is a cross-sectional view showing a state where a push button of the thermostat shown in FIG. 1 is pushed.

FIG. 3 is a cross-sectional view of the main part when the thermostat cap shown in FIG. 1 is attached.

[FIG. 4] FIG. 4 is a cross-sectional view of the main part of the thermostat shown in FIG. 1 before the defrost pin molding cage.

FIG. 5 is a cross-sectional view of the main part of the thermostat shown in FIG. 1 after a defrost pin forming cache.

FIG. 6 is a cross-sectional view of a conventional thermostat.

FIG. 7 is an enlarged plan view of a defrost lever of a conventional thermostat.

FIG. 8 is an enlarged cross-sectional view of a connecting portion between a defrost pin and a defrost lever of a conventional thermostat.

Explanation of symbols

[0014] 21 container

22 Bellows

23.

24 L-shaped lever

27 switches

28 Spacer

29 Spring

31 Adjustment

32 Cam through hole

33 cams

34 Adjustment plate

35 Roller body

36 Adjustment screw 37 Defroster

37a Deflection lever fulcrum

37b Defroster lever tab

37c Defrost lever arm

37d circular hole in defrost lever

38 Defrost pin

38a Defrosted pin step

38c Lower end of defrost pin

38d cap

BEST MODE FOR CARRYING OUT THE INVENTION

[0015] The thermostat of the present invention comprises a bottom and a substantially U-shaped container frame having two side forces facing each other, a bellows that expands and contracts by sensing a change in the internal temperature, and a lower end abutting on the other end of the bellows. Is an L-shaped lever that operates the switch, an adjustment lever that changes its inclination by the rotation of a cam with a through hole, and a spring that connects the L-shaped lever and the adjustment lever to counter the change in bellows. , One end locked to the adjustment lever and the other end pivotably locked, an adjustment plate that holds the roller body, an adjustment screw that can change the distance between the adjustment lever and the adjustment plate, and a cam through hole An up and down defrost pin with a stepped through part, a pivot that is pivoted so that one end can be pivoted, and a claw that has an inclined surface that can contact the roller body at the other end and an L-shaped Differential equipped with an arm that can contact the lever A thermostat in which a strobe is arranged and the end of the defrost pin is engaged with the end face of the defrost lever so that the end face of the defrost lever is larger than the shaft diameter of the defrost pin so that the defrost pin can pass through. And a hole smaller than the diameter of the step part of a defrost pin is provided. In this way, since there is a clearance between the defrost pin shaft and the hole of the defrost lever, the defrost pin operates along the through hole of the cam vertically upward, and engages with the defrost pin. The frictional force of the defrost pin and the cam through hole is not applied to the lever. As a result, it is possible to achieve a stable defrosting recovery temperature with little variation in operation.

In the thermostat of the present invention, after the defrost pin is passed through the defrost lever hole, the lower end portion of the defrost pin is attached with a cap larger than the defrost lever hole. in this way Thus, it is possible to easily assemble the parts without using a special jig or the like, and it is possible to reduce the number of assembling steps and improve the assembling quality.

[0017] Further, in the thermostat of the present invention, after the defrost pin is passed through the defrost lever hole, the lower end portion of the defrost pin is molded to a diameter larger than that of the defrost lever hole. In this way, parts can be easily assembled without using special jigs and the number of parts does not increase. In other words, it is possible to shorten the assembly man-hours, improve the assembly quality, and realize a low-cost thermostat.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the drawings are schematic views and do not accurately show the positional relationships. Further, the same components as those described in the background art are denoted by the same reference numerals, and detailed description thereof is omitted. The thermostat of the present invention is a manual defrosting type thermostat mounted on a direct cooling refrigerator. Parts required for a manual defrost mechanism (defrost mechanism) are called defrost pins and defrost levers. The defrost pin transmits the push button operation (up and down movement) to the defrost lever. The defrost lever also has a function to transmit the movement of the defrost pin to the lever and turn the switch on and off. As a material for the defrost pin or defrost lever, a known material such as stainless steel or iron can be used.

[0019] (Embodiment)

This embodiment will be described with reference to FIGS. FIG. 1 is a cross-sectional view showing a normal state of the thermostat in the embodiment of the present invention. FIG. 2 is a sectional view showing a state in which the push button of the thermostat shown in FIG. 1 is pushed. Fig. 3 is a cross-sectional view of the main part when the thermostat cap shown in Fig. 1 is attached. Fig. 4 is a cross-sectional view of the main part of the thermostat shown in Fig. 1 before defrost pin forming calorie. FIG. 5 is a cross-sectional view of the main part of the thermostat shown in FIG.

[0020] The container frame 21 is substantially U-shaped. For example, the bellows 22 expands and contracts by detecting the temperature inside the refrigerator. A bellows tube 23 is connected to a bellows tube 23. The L-shaped lever 24 is rotatably provided by a fulcrum 24a. The lower end 24 b of the lever 24 abuts on the free end 22 a of the bellows 22. The other end 24c of the lever 24 is engaged with a spacer 28 for performing a switching operation of a switch 27 for opening and closing the fixed contact 25 and the movable contact 26. More In addition, one end of the temperature setting spring 29 is locked to one end 24 d of the lever 24. The other end of the temperature setting spring 29 is locked to the adjustment lever 31 via the adjustment screw 30. The adjustment lever ₃₁ is rotatably provided on the casing 21 by a lower fulcrum 31a, and its upper end is in pressure contact with a temperature setting cam 33 having a through hole 32. One end of the adjustment plate 34 is locked to the adjustment lever 31, and the other end holds a roller body 35 that is rotatably locked. The adjustment plate 34 holds an adjustment screw 36 that can change the distance between the adjustment lever 31 and the adjustment plate 34. The defrost lever 37 is rotatably provided by a fulcrum 37a. The defrost lever 37 is threaded through the through hole 32 of the cam and engages with a defrost pin 38 having a stepped portion 38a arranged to be movable up and down. One end of the defrost lever 37 is provided with a claw portion 37b having a sloped body capable of coming into contact with the roller body 35, and an arm 37c capable of contacting the lever 31 is provided at the other end. Further, a circular hole 37 d larger than the shaft diameter of the defrost bin 38 is provided on the end surface portion of the defrost lever 37.

The operation of the thermostat configured as described above will be described below.

[0022] First, when the temperature of the temperature sensing part rises, the gas pressure in the capillary tube 23 rises, causing the bellows 22 to expand. As a result, the L-shaped lever 24 rotates around the fulcrum 24a in the direction of arrow A in FIG. 1 to counter the elastic force of the spring 29 (corresponding to the set temperature) set by the adjusting screw 30. When the temperature sensing unit exceeds the set temperature, the switch 27 is operated via the spacer 28, the fixed contact 25 and the movable contact 26 are connected, and the power circuit is energized.

Next, when the temperature of the temperature sensing unit decreases, the bellows 22 contracts, and the lever 24 rotates in the direction of arrow B in FIG. 1 about the fulcrum 24a by the elastic force of the spring 29. At the same time, the pressure applied by the spacer 28 is reduced, the switch 27 is operated, the fixed contact 25 and the movable contact 26 are separated, and the power supply circuit is turned off.

[0024] The above is a general force of the thermostat that acts as a function of temperature. Next, the action of the defrost pin 38 will be described. By pushing the defrost pin 38 when the switch 27 is in the on state, the defrost lever 37 moves in a counterclockwise direction around the fulcrum 37a by being piled on the force of the spring 29. Further, when the lever 24 is pushed by the arm 37c of the defrost lever 37, the arc 27 moves counterclockwise around the fulcrum 24a of the lever 24, so that the switch 27 is turned off via the spacer 28. At this time it had a slope of defrost lever 37 The claw portion 37b is latched with the roller integrated body 35 held by the adjustment plate 34 attached to the adjustment lever 31, and keeps the off state in the pressed position.

[0025] On the other hand, when the switch 27 changes its off-state force to the on-state, the switch 27 is in the off-state, so that the bellows 22 expands due to the temperature rise of the temperature sensing unit. As a result, the lever 24 performs an arc motion clockwise around the fulcrum 24a. At this time, the arm 37c of the defrost lever 37 is pushed upward by the lever 24, and the defrost lever 37 moves in a circular arc clockwise. When a force greater than the resistance of the spring 28 is applied to the latch portion, the latch is released and the defrost pin 38 returns to its original position, and the switch 27 is moved via the spacer 28 by the rotation of the lever 24. Turns on.

[0026] As described above, in this embodiment, the bottom and the substantially U-shaped container frame having two side forces facing each other, the bellows that expands and contracts by sensing temperature changes, and the lower end abuts the bellows. At the other end, an L-shaped lever that operates the switch, an adjustment lever that changes its inclination by the rotation of a cam with a through hole, and an L-shaped lever and an adjustment lever are connected to counter the change in bellows. A spring, an adjustment plate that holds a roller body, one end of which is locked by the adjustment lever and the other end of which is freely rotatable, an adjustment screw that can change the interval between the adjustment lever and the adjustment plate, and a cam A differential pin that can be moved up and down, having a stepped portion that passes through the through-hole, and a claw portion that is pivotally supported so that one end can be pivoted and has a slope that can contact the roller body at the other end. Equipped with an L-shaped lever and arm that can contact A thermostat in which a defrost lever is arranged and the end of the defrost pin is engaged with the end face of the defrost lever so that the defrost pin can be passed through the end face of the defrost lever from the shaft diameter of the defrost pin. A thermostat with a hole that is larger and smaller than the diameter of the stepped portion of the defrost pin was described. Thus, since the defrost pin operates along the through hole of the cam vertically upward by having a clearance between the defrost pin shaft and the hole of the defrost lever, the defrost lever engaged with the defrost pin The frictional force between the defrost pin and the cam through hole is not applied. As a result, it is possible to provide a thermostat excellent in quality that realizes a stable defrosting return temperature with little fluctuation in operating temperature.

In the present embodiment, as shown in FIG. 3, after the defrost pin 38 is passed through the defrost lever hole 37d, the defrost pin lower end 38c is larger than the defrost lever hole 37d. Wear Yap 38d. In this way, it is possible to easily assemble parts without using a special jig or the like, and it is possible to provide an inexpensive thermostat with a small number of assembly steps.

Furthermore, in the present embodiment, as shown in FIGS. 4 and 5, after the defrost pin 38 is passed through the defrost lever hole 37d, the lower end portion 38c of the defrost pin is larger in diameter than the defrost lever hole 37d. To be processed. As the molding method, compression molding is preferred. In this way, it is possible to easily assemble parts without using special jigs, etc., and an inexpensive thermostat with fewer assembly steps and fewer parts without increasing the number of parts. Can be provided.

Note that the present invention is not limited to the present embodiment.

Industrial applicability

[0030] Since the thermostat that is useful in the present invention can realize a stable defrosting return temperature with little temperature fluctuation, it can be applied to applications such as refrigerators and cold storages.

Claims

The scope of the claims

[1] U-shaped container frame that is the bottom and two opposing side forces;

Bellows that expands and contracts by sensing temperature changes in the chamber,

An L-shaped lever with the lower end abutting the bellows and the other end operating the switch;

An adjustment lever whose inclination changes by rotation of a cam having a through hole;

A spring that couples the L-shaped lever and the adjustment lever to counter the change in the bellows;

An adjustment plate for holding the roller unit, one end of which is locked to the adjustment lever and the other end of which is rotatably locked;

An adjustment screw that allows the interval between the adjustment lever and the adjustment plate to be variable; a defrost pin that has a stepped portion that passes through the through hole of the cam; and is pivotally supported so that one end can be rotated, The other end has a claw portion having a slope that can come into contact with the roller body,

A defrost lever provided with an arm that can contact the L-shaped lever, and an end portion of the defrost pin engaged with the end surface of the defrost lever so as to face the thermostat,

A thermostat characterized in that a hole larger than the diameter of the defrost pin shaft and smaller than the diameter of the stepped portion of the defrost pin is provided in the end surface of the defrost lever so that the defrost pin can be inserted.

[2] The thermostat according to claim 1, wherein a cap larger than a diameter of the defrost lever hole is attached to a lower end portion of the defrost pin after passing the defrost pin through the hole of the defrost lever.

3. The thermostat according to claim 1, wherein after the defrost pin is passed through the defrost lever hole, a lower end portion of the defrost pin is formed and processed to have a diameter larger than that of the defrost lever hole.