Inverted bimetal thermometer

Abstract

The utility model belongs to the field of temperature sensing equipment, and particularly relates to an inverted bimetal thermometer which comprises a gauge head 1, the bottom of the gauge head 1 is fixedly connected with an outer protective tube 2, a sleeving piece 3 is arranged in the outer protective tube 2, the top of the sleeving piece 3 is fixedly connected with the gauge head 1, a rotating shaft 4 is arranged in the sleeving piece 3 in a sleeving mode, and the top of the rotating shaft 4 is fixedly connected with a pointer 41. A shaft rod of the rotating shaft 4 is fixedly connected with one end of a bimetal spring 5, the other end of the bimetal spring 5 surrounds the rotating shaft 4 and is spirally arranged in the direction away from or close to the meter head 1, a first-layer spiral structure is formed, and the end of the first-layer spiral structure spirally expands outwards in the radial direction. The double-metal spring 5 is spirally arranged around the first-layer spiral structure in the direction opposite to the first-layer spiral structure to form a second-layer spiral structure, by parity of reasoning, n layers of spiral structures are formed, n is a natural number and is larger than or equal to 2, and the end of the nth-layer spiral structure in the double-metal spring 5 is fixedly connected with the sleeving piece 3.

Description

Technical Field

[0001] This invention belongs to the field of temperature sensing devices, and specifically relates to an inverted bimetallic thermometer. Background Technology

[0002] A bimetallic thermometer combines two metals with different coefficients of linear expansion. One end is fixed, and when the temperature changes, the two metals expand differently, causing the pointer to deflect to indicate the temperature.

[0003] Existing bimetallic thermometers, referencing CN202122276624.4, have a bimetallic spring with one end fixed to the pointer shaft and the other end extending and fixed to the outer protective tube. This structure has the following two problems:

[0004] 1. Along the length of the outer protective tube, the bimetallic spring occupies a large space, making it unsuitable for installation in small spaces and temperature sensing conditions. The bimetallic spring itself also needs to be long enough to meet the measurement accuracy.

[0005] 2. During production, because the bimetallic spring needs to be fixed to the outer protective tube, the meter head, shaft, and pointer need to be assembled. After one end of the bimetallic spring is fixed to the shaft, the outer protective tube with an open bottom is first fixed to the bottom of the meter head. Then, the bimetallic spring is welded to the inner wall of the outer protective tube, and the bottom opening of the outer protective tube is sealed with a plug. The weld seam left on the outside is not aesthetically pleasing and requires further grinding. It is also possible that the secondary processing will result in inadequate sealing and defective products. Furthermore, when the bimetallic spring deforms and fails, the outer protective tube must be completely disassembled along with the bimetallic spring and shaft for replacement, which increases maintenance costs. Summary of the Invention

[0006] To address the aforementioned problems in manufacturing caused by the limited length of the bimetallic thermometer, including the need for a sufficiently long bimetallic spring within the limited space of the bimetallic thermometer and the connection structure of the bimetallic thermometer, this invention provides an inverted bimetallic thermometer.

[0007] The objective of this invention is achieved in the following manner: an inverted bimetallic thermometer includes a meter head 1, with an outer protective tube 2 fixedly connected to the bottom of the meter head 1. A sleeve 3 is disposed inside the outer protective tube 2, with the meter head 1 fixedly connected to the top of the sleeve 3. A rotating shaft 4 is sleeved inside the sleeve 3, with a pointer 41 fixedly connected to the top of the rotating shaft 4. One end of a bimetallic spring 5 is fixedly connected to the shaft of the rotating shaft 4. The other end of the bimetallic spring 5 is spirally arranged around the rotating shaft 4 in a direction away from or towards the meter head 1, forming a first spiral structure. The end of the first spiral structure spirals outward radially and spirals around the first spiral structure in a direction opposite to the first spiral structure, forming a second spiral structure. This process is repeated to form n spiral structures, where n is a natural number and n≥2. The end of the nth spiral structure of the bimetallic spring 5 is fixedly connected to the sleeve 3.

[0008] Furthermore, from the time the bimetallic spring 5 is fixed to one end of the rotating shaft 4, to the time the bimetallic spring 5 is fixed to one end of the sleeve 3, the extension direction of the helix of the bimetallic spring 5 changes, while the rotation direction remains unchanged.

[0009] Furthermore, in the bimetallic spring 5, a guide cylinder 6 is provided between the spiral structures of adjacent layers. The guide cylinder 6 separates the spiral structures of adjacent layers, and the guide cylinder 6 is fixedly connected to the sleeve 3 or the outer protective tube 2.

[0010] Furthermore, the gap between the guide cylinder 6 and the spiral structure of the adjacent layer is greater than or equal to 1 mm.

[0011] Furthermore, one end of the inner ring bimetallic spring 51 is fixedly connected to the shaft 4. The other end of the inner ring bimetallic spring 51 is spirally arranged around the shaft 4 and in a direction away from the meter head 1. At the end furthest from the meter head 1, it spirals outward radially and is fixedly connected to one end of the outer ring bimetallic spring 52. The other end of the outer ring bimetallic spring 52 is spirally arranged around the inner ring bimetallic spring 51 and in a direction closer to the meter head 1. The other end of the outer ring bimetallic spring 52 is fixedly connected to the sleeve 3. A guide cylinder 6 is provided between the inner ring bimetallic spring 51 and the outer ring bimetallic spring 52. The top end of the guide cylinder 6 is fixedly connected to the bottom end of the sleeve 3.

[0012] Compared with existing technologies, this invention uses a multi-layer spiral bimetallic spring, which solves the problem of space utilization in the length direction of the outer protective tube. Furthermore, the two ends of the bimetallic spring are respectively fixed to the sleeve under the meter head and the rotating shaft, without interfering with the outer protective tube, which is beneficial for manufacturing and later maintenance. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the double-layer bimetallic spring scheme;

[0014] Figure 2 This is a schematic diagram of the outer layer of the double-layer bimetallic spring scheme;

[0015] Figure 3 This is a schematic diagram of the inner layer of the double-layer bimetallic spring scheme;

[0016] Figure 4 This is a schematic diagram of the inner layer structure of another scheme for a double-layer bimetallic spring;

[0017] Figure 5 This is a schematic diagram of the inner layer of a three-layer bimetallic spring scheme.

[0018] The components include: 1. Gauge head; 2. Outer protective tube; 3. Sleeve; 4. Rotating shaft; 41. Pointer; 5. Bimetallic spring; 51. Inner ring bimetallic spring; 52. Outer ring bimetallic spring; 53. Variable diameter section; and 6. Guide cylinder. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] In this invention, unless otherwise explicitly specified and limited, the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention.

[0021] As attached Figure 1-5 As shown, an inverted bimetallic thermometer includes a meter head 1. An outer protective tube 2 is fixedly connected to the bottom of the meter head 1. A sleeve 3 is disposed inside the outer protective tube 2, and the meter head 1 is fixedly connected to the top of the sleeve 3. A rotating shaft 4 is sleeved inside the sleeve 3, and a pointer 41 is fixedly connected to the top of the rotating shaft 4. Specifically, the meter head 1 includes a dial, and the sleeve 3 is snapped or welded to the center of the dial. A through hole is provided in the center of the sleeve 3 for the rotating shaft 4 to pass through, ensuring that the rotating shaft 4 can rotate freely. One end of a bimetallic spring 5 is fixedly connected to the shaft of the rotating shaft 4, and the other end of the bimetallic spring 5 is spirally arranged around the rotating shaft 4 in a direction away from or towards the meter head 1, forming a first layer of spiral. The first spiral structure has a radially outward spiraling end that forms a variable diameter section 53. A second spiral structure is formed around the first spiral structure and spiraled in the opposite direction to the first spiral structure. One end of the second spiral structure is fixed to the first spiral structure, and the other end is spiraled in the opposite direction to the second spiral structure to form a third spiral structure. Here, "opposite direction" refers to the direction of the spiral line extension of the spiral structure, not the direction of spiral rotation. This process is repeated to form n spiral structures, where n is a natural number and n≥2. The end of the nth spiral structure in the bimetallic spring 5 is fixedly connected to the sleeve 3.

[0022] Compared with the prior art, the present invention adopts a multi-layer spiral structure bimetallic spring 5, which solves the problem of space utilization in the length direction of the outer protective tube 2. Moreover, the two ends of the bimetallic spring 5 are respectively fixed to the sleeve 3 under the meter head and the rotating shaft 4, which do not interfere with the outer protective tube 2, which is beneficial to manufacturing and later maintenance.

[0023] Preferably, each spiral structure, except for the variable diameter section 53 at the end, does not contact or overlap with itself in the radial direction. The purpose of this design is to prevent interference caused by the overlap of each spiral structure in the radial direction when the temperature changes, which would lead to inaccurate measurement results.

[0024] Existing technologies have bimetallic spring structures that only extend radially in a spiral without axial extension. The gaps between layers are extremely small, which easily leads to the aforementioned problems. In this solution, by forming a multi-layer structure, a three-dimensional arrangement of bimetallic springs is formed. The axial length is controllable, and the radial length is also controllable. The gap between adjacent spiral structures is preferably greater than or equal to 2mm, that is, the variable diameter section 53 should produce a variable diameter effect of 2mm or more. This gap can be determined by the diameter of each spiral structure itself, or it can be further limited by the "guide cylinder 6" mentioned later.

[0025] Furthermore, from the point where the bimetallic spring 5 is fixed to one end of the rotating shaft 4, to the point where the bimetallic spring 5 is fixed to one end of the sleeve 3, the extension direction of the helix of the bimetallic spring 5 changes, while the rotation direction remains unchanged. Here, we take... Figure 1-3 For example, the diagram shows the structure of the double-layer bimetallic spring scheme. The inner bimetallic spring 51 and the outer bimetallic spring 52 have opposite spiral directions. However, in the continuous structure from the inner bimetallic spring 51 fixed to one end of the rotating shaft 4 to the outer bimetallic spring 52 fixed to one end of the sleeve 3, from the top view, the bimetallic spring 51 only rotates and extends in a counterclockwise direction, and changes its extension direction at the variable diameter part 53.

[0026] Further details are attached. Figure 4-5 As shown, in the bimetallic spring 5, a guide cylinder 6 is provided between the adjacent spiral structures. The guide cylinder 6 separates the adjacent spiral structures. The guide cylinder 6 is fixedly connected to the sleeve 3 or the outer protective tube 2. The purpose of the guide cylinder 6 is that if the temperature distribution is uneven during temperature sensing, it will cause the bimetallic spring 5 to tilt. After the multi-layer bimetallic spring is tilted, it is more likely to cause misalignment. Therefore, the guide cylinder 6 is used to position each layer of bimetallic spring 5. The guide cylinder 6 is preferably made of stainless steel with a thickness of less than or equal to 0.5 mm and a smooth surface, so as to minimize the impact on the opening and closing of the bimetallic spring 5. Furthermore, the gap between the guide cylinder 6 and the adjacent spiral structure is greater than or equal to 1 mm. This value is determined according to the actual possible variation of each spiral structure.

[0027] For the two-layer spiral structure with the variable diameter section 53 located at the distal end, such as Figure 4 The double-layer spiral structure shown has the guide cylinder 6 fixedly connected to the bottom of the sleeve 3. For the double-layer spiral structure where the variable diameter section 53 is located near the end, as... Figure 5The three-layer spiral structure shown has a guide cylinder 6 fixedly connected to the bottom of the outer protective tube 2. During installation, the guide cylinder 6 of the outer protective tube 2 is inserted between the two spiral structures.

[0028] Furthermore, as a specific solution to the above abstract scheme, as shown in the appendix... Figure 1-3 As shown, one end of the inner ring bimetallic spring 51 is fixedly connected to the shaft 4. The other end of the inner ring bimetallic spring 51 is spirally arranged around the shaft 4 and in a direction away from the meter head 1. At the end furthest from the meter head 1, it spirals outward radially and is fixedly connected to one end of the outer ring bimetallic spring 52. The other end of the outer ring bimetallic spring 52 is spirally arranged around the inner ring bimetallic spring 51 and in a direction closer to the meter head 1. The other end of the outer ring bimetallic spring 52 is fixedly connected to the sleeve 3. A guide cylinder 6 is provided between the inner ring bimetallic spring 51 and the outer ring bimetallic spring 52. The top end of the guide cylinder 6 is fixedly connected to the bottom end of the sleeve 3.

[0029] A method for producing an inverted bimetallic thermometer as described above, the method comprising the following steps:

[0030] S1. Prepare the dial of the thermometer, fix the connecting sleeve 3 in the middle of the dial, let one end of the rotating shaft 4 pass through the connecting sleeve 3 and fix the pointer 41, and fix the outer protective shell on the side of the dial with the pointer 41 to form the meter head 1.

[0031] S2. Prepare at least two bimetallic spiral strips with different diameters, arranged in order of diameter size, with adjacent bimetallic spiral strips having opposite spiral directions;

[0032] S3. Fix one end of the smallest diameter bimetallic spiral strip to the shaft body of the rotating shaft 4, and bend the other end outward to form a variable diameter part 53 with a gradually increasing diameter and outward extension. Fix one end of the second smallest diameter bimetallic spiral strip to it. This fixing connection is preferably welded, and a weld is formed on the outer surface to prevent a fixed relationship between the inner metal strip and the outer metal strip. That is, if the two metal strips are brass and stainless steel, the brass strip is connected as a whole, and the stainless steel strip is connected as a whole. And so on to form an n-layer spiral structure bimetallic spring 5. The end of the nth spiral structure is fixedly connected to the side of the sleeve 3.

[0033] S4. Sleeve the outer protective tube 2 over the sleeve 3 and the bimetallic spring 5, and fix it to the bottom of the meter head 1.

[0034] Furthermore, whenever a diameter change portion 53 is generated at the far end, a guide cylinder 6 with a size corresponding to the spiral structure of the corresponding layer is welded to the bottom of the sleeve 3. Whenever a diameter change portion 53 is generated at the near end, a guide cylinder 6 with a size corresponding to the spiral structure of the corresponding layer is welded to the bottom of the inner side of the outer protective tube 2. When the outer protective tube 2 is installed, the guide cylinder 6 is inserted into the multi-layer spiral structure.

[0035] The term "far" refers to the direction away from meter 1, and "near" refers to the direction close to meter 1.

[0036] The above description is only a preferred embodiment of the present invention. It should be noted that those skilled in the art can make several changes and improvements without departing from the overall concept of the present invention, and these should also be considered within the scope of protection of the present invention.

Claims

1. An inverted bimetallic thermometer, comprising a meter head (1), wherein an outer protective tube (2) is fixedly connected to the bottom of the meter head (1), characterized in that: The outer protective tube (2) is provided with a sleeve (3), the top of the sleeve (3) is fixedly connected to the meter head (1), the sleeve (3) is sleeved with a rotating shaft (4), the top of the rotating shaft (4) is fixedly connected to the pointer (41), one end of the bimetallic spring (5) is fixedly connected to the shaft of the rotating shaft (4), the other end of the bimetallic spring (5) is spirally arranged around the rotating shaft (4) and in a direction away from or close to the meter head (1) to form a first layer of spiral structure. The end of the first layer of spiral structure spirals outward in a radial direction and spirals around the first layer of spiral structure in a direction opposite to the first layer of spiral structure to form a second layer of spiral structure, and so on to form n layers of spiral structure, where n is a natural number and n≥2. The end of the nth layer of spiral structure in the bimetallic spring (5) is fixedly connected to the sleeve (3).

2. The inverted bimetallic thermometer as described in claim 1, characterized in that: From the moment the bimetallic spring (5) is fixed to one end of the rotating shaft (4), to the moment the bimetallic spring (5) is fixed to one end of the sleeve (3), the extension direction of the helix of the bimetallic spring (5) changes, while the rotation direction remains unchanged.

3. An inverted bimetallic thermometer as defined in claim 1, wherein: In the bimetallic spring (5), a guide cylinder (6) is provided between the spiral structures of adjacent layers. The guide cylinder (6) separates the spiral structures of adjacent layers. The guide cylinder (6) is fixedly connected to the sleeve (3) or the outer protective tube (2).

4. The inverted bimetallic thermometer as described in claim 3, characterized in that: The gap between the guide cylinder (6) and the spiral structure of the adjacent layer is greater than or equal to 1 mm.

5. The inverted bimetallic thermometer as described in claim 3, characterized in that: One end of the inner ring bimetallic spring (51) is fixedly connected to the shaft (4). The other end of the inner ring bimetallic spring (51) is spirally arranged around the shaft (4) and in a direction away from the meter head (1). At the end furthest from the meter head (1), it spirals outward in a radial direction and is fixedly connected to one end of the outer ring bimetallic spring (52). The other end of the outer ring bimetallic spring (52) is spirally arranged around the inner ring bimetallic spring (51) and in a direction closer to the meter head (1). The other end of the outer ring bimetallic spring (52) is fixedly connected to the sleeve (3). A guide cylinder (6) is provided between the inner ring bimetallic spring (51) and the outer ring bimetallic spring (52). The top end of the guide cylinder (6) is fixedly connected to the bottom end of the sleeve (3).

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