Anti-deflection structure of compressor exhaust valve

Abstract

The present invention discloses an anti-deflection structure of an exhaust valve of a compressor, comprising a crankcase provided with a cylinder hole, an exhaust valve assembly provided on the crankcase, the exhaust valve assembly comprising a valve plate covering the cylinder hole, an exhaust channel connected to the cylinder hole provided on the valve plate, an outlet of the exhaust channel covered with a tongue reed, a tail of the tongue reed provided with a pressing portion connected to the valve plate; by redesigning the arrangement of the tongue reed in the exhaust valve assembly, adjusting the angle between the line connecting the center of the cylinder hole and the center of the exhaust channel and the geometric symmetry axis of the tongue reed, the lever arm of the deflection moment is shortened, thereby reducing or even eliminating the deflection moment of the exhaust valve caused by the uneven flow field.

Description

Technical Field

[0001] The invention relates to the technical field of compressor manufacturing, and in particular to an anti-deflection structure of a compressor exhaust valve. Background Art

[0002] Existing refrigerators or freezers all use reciprocating compressors for refrigeration; reciprocating compressors are driven by power to discharge high-pressure gas to the condenser of the box through the exhaust valve. The exhaust valve of the compressor generally adopts a tongue spring structure. That is, one end is fixed; the other end is free to cover the exhaust channel opening, and can be opened and closed freely under the action of pressure difference. As a precision core component of the compressor, the exhaust valve is subjected to alternating impact loads; root bending fatigue failure and head slapping fatigue failure often occur. How to improve the reliability of the exhaust valve has always been the technical key to the development of the compressor industry.

[0003] Exhaust valve deflection caused by insufficient compression of the exhaust valve root is considered to be a key factor affecting exhaust valve failure. Since the exhaust passage is generally not designed at the center of the cylinder, the airflow in the exhaust passage is uneven; the uneven airflow will cause the exhaust valve to be subjected to a deflection torque. If the exhaust valve root is not completely compressed, the exhaust valve will deflect around the root; after deflection, stress concentration is likely to occur and fatigue failure will occur in a short period of time. The current solution is to increase the clamping force as much as possible to prevent the exhaust valve from deflecting, such as riveting and welding the exhaust valve root; although there is a certain effect, it requires strict control of the exhaust valve root compression design and assembly process, which is costly and cannot completely eliminate the exhaust valve deflection.

[0004] In addition, Chinese patent publication number CN205001155U, published on January 27, 2016, entitled "Anti-deflection structure of exhaust valve plate of refrigerator compressor", discloses an anti-deflection structure of exhaust valve plate of refrigerator compressor, including exhaust valve plate, valve plate and limiter; the exhaust valve plate is an asymmetric structure, and the two sides of the exhaust valve plate have different stiffness. During assembly, the side with greater rigidity of the exhaust valve plate is installed near the center of the cylinder, which increases the difficulty of opening this side and prevents the exhaust valve plate from deflecting during the opening process. This structural solution is not designed from the perspective of reducing or eliminating the deflection torque, and still cannot solve the problem. Summary of the invention

[0005] In response to the problem mentioned in the background technology that the exhaust valve plate suffers fatigue failure due to the deflection torque it is subjected to during operation, the present invention provides an anti-deflection structure for a compressor exhaust valve. By redesigning the arrangement of the tongue spring in the exhaust valve assembly and adjusting the angle between the line connecting the center of the cylinder hole and the center of the exhaust channel and the geometric symmetry axis of the tongue spring, the lever arm of the deflection torque is shortened, thereby reducing or even eliminating the deflection torque of the exhaust valve caused by the uneven flow field.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A deflection prevention structure of a compressor exhaust valve, comprising a crankcase provided with a cylinder hole, an exhaust valve assembly provided on the crankcase, the exhaust valve assembly comprising a valve plate covering the cylinder hole, an exhaust passage communicating with the cylinder hole provided on the valve plate, a tongue reed covering an outlet of the exhaust passage, and a pressing portion connected to the valve plate provided at a tail of the tongue reed;

[0008] The deflection moment M borne by the tongue reed is (F1-F2)*h, F1 is the airflow pressure on the side of the tongue reed close to the center of the cylinder hole, F2 is the airflow pressure on the side of the tongue reed away from the center of the cylinder hole, and h is the distance from the deflection force formed by F1 and F2 to the center of the pressing part; wherein, h=L*Sinα; wherein L is the distance between the center of the tongue reed and the center of the pressing part; α is the angle between the line connecting the center of the cylinder hole and the center of the exhaust channel and the geometric symmetry axis of the tongue reed; wherein, α≤30°. Starting from the cause of the generation of the deflection torque, the present application finds that the tongue spring used to shield the outlet of the exhaust channel bears pressures in opposite directions of F1 and F2 respectively, and the exhaust channel is generally not designed at the center of the cylinder, resulting in uneven airflow in the exhaust channel. Therefore, F1 and F2 will form a resultant force, which is the deflection force that can generate the deflection torque. The deflection force exists during the operation of the crankcase and has an uncertain value. Therefore, the deflection torque can be controlled by changing the lever arm corresponding to the deflection force. The present application changes the lever arm size by changing the angle between the line connecting the center of the cylinder hole and the center of the exhaust channel and the geometric symmetry axis of the tongue spring, thereby reducing the deflection torque, effectively improving the working reliability of the exhaust valve, and avoiding the deflection torque affecting the service life of the exhaust valve.

[0009] Preferably, the line connecting the center of the cylinder hole and the center of the exhaust channel coincides with the geometric symmetry axis of the tongue spring, and α=0°. When the line connecting the center of the cylinder hole and the center of the exhaust channel coincides with the geometric symmetry axis of the tongue spring, the force arm is zero, and the deflection moment caused by the uneven flow field is completely eliminated, avoiding the stress concentration caused by the deflection, thereby improving the service life of the exhaust valve.

[0010] Furthermore, the exhaust valve assembly includes a limit plate, which presses and fixes the pressing part to the outer side of the valve plate, and the tongue spring fits and covers the outlet of the exhaust channel. The limit plate is used to limit the lift of the tongue spring, and the limit plate is fixedly installed on the valve plate to lock the position of the pressing part.

[0011] Preferably, the tongue spring includes a sealing portion and a spring plate portion, wherein the sealing portion is connected to the pressing portion through the spring plate portion, and the diameter of the sealing portion is larger than the diameter of the exhaust passage outlet. When the sealing portion is impacted by the flow field, the spring plate portion is bent to open the valve for exhaust, while the sealing portion is used to ensure that the exhaust passage is completely closed when no gas is discharged, thereby ensuring the sealing property of the cylinder.

[0012] Preferably, a reinforcing rib is provided at the joint of the pressing part and the spring plate part, and a clearance groove is provided on the valve plate corresponding to the reinforcing rib. The reinforcing rib is used to reduce the stress concentration at the bend of the tongue spring and reduce the possibility of fatigue failure of the tongue spring, while the clearance groove is used to ensure that the exhaust channel is kept closed after the tongue spring is reset, and no gap will appear due to the interference of the reinforcing rib.

[0013] Furthermore, the reinforcing ribs are arranged along the width direction of the tongue spring.

[0014] Preferably, the two sides of the reinforcing rib are smoothly transitioned to connect the pressing part and the spring plate part respectively.

[0015] The reinforcing ribs are used to strengthen the joint position between the spring plate portion and the clamping portion, ensure its fatigue resistance during frequent bending of the tongue spring, and connect the spring plate portion and the clamping portion in a smooth transition manner to avoid stress concentration at the connection and fatigue fracture.

[0016] Therefore, the present invention has the following beneficial effects: (1) by redesigning the arrangement of the tongue spring in the exhaust valve assembly and adjusting the angle between the line connecting the center of the cylinder hole and the center of the exhaust passage and the geometric symmetry axis of the tongue spring, the arm of the deflection moment is shortened, thereby reducing or even eliminating the deflection moment of the exhaust valve caused by the uneven flow field; (2) the reinforcing ribs are used to strengthen the joint position of the spring plate portion and the clamping portion, to ensure its fatigue resistance during the frequent bending of the tongue spring, and to connect the spring plate portion and the clamping portion in a smooth transition manner, to avoid stress concentration at the connection and fatigue fracture. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural schematic diagram of the present invention.

[0018] Figure 2 It is a schematic diagram of the arrangement of the exhaust valve assembly in the prior art.

[0019] Figure 3 Schematic diagram of the arrangement of the exhaust valve assembly in Example 1.

[0020] Figure 4 Schematic diagram of the arrangement of the exhaust valve assembly in Example 2.

[0021] In the figure: 100 crankcase, 101 cylinder hole, 200 piston, 1 valve plate, 11 exhaust channel, 12 give way groove, 2 tongue spring, 21 sealing part, 22 spring plate part, 3 pressing part, 4 limit plate, 5 reinforcing rib, 6 line connecting the center of cylinder hole and the center of exhaust channel, 7 geometric symmetry axis of tongue spring. DETAILED DESCRIPTION

[0022] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0023] Example 1

[0024] like Figure 2 As shown, a deflection prevention structure of a compressor exhaust valve comprises a crankcase 100 provided with a cylinder hole 101, an exhaust valve assembly is provided on the crankcase 100, and the exhaust valve assembly comprises a valve plate 1 covering the cylinder hole 101, an exhaust passage 11 connected to the cylinder hole 101 is provided on the valve plate 1, an outlet of the exhaust passage 11 is covered with a tongue reed 2, and a pressing portion 3 connected to the valve plate 1 is provided at the tail of the tongue reed 2; wherein, the deflection moment M borne by the tongue reed 2 = (F1-F2)*h, F1 is the air flow pressure of the tongue reed 2 close to the center of the cylinder hole, F2 is the air flow pressure of the tongue reed 2 away from the center of the cylinder hole, and h is the distance from the deflection resultant force formed by F1 and F2 to the center of the pressing portion 3; wherein, h = L*Sinα; wherein, L is the distance between the center of the tongue reed 2 and the center of the pressing portion 3; α is the angle between the line 6 connecting the center of the cylinder hole and the center of the exhaust passage and the geometric symmetry axis of the tongue reed 2; as shown Figure 3As shown, in this embodiment, α=30°. A reciprocating piston 200 is arranged in the cylinder hole of the crankcase 100. The exhaust valve assembly is opened during the exhaust stroke of the piston 200. In this scheme, starting from the cause of the generation of the deflection torque, it is found that the tongue spring 2 used to shield the outlet of the exhaust channel 11 bears pressures in opposite directions of F1 and F2 respectively, and the exhaust channel 11 is generally not designed at the center of the cylinder, resulting in uneven air flow in the exhaust channel, so F1 and F2 will form a resultant force, which is the deflection force that can generate the deflection torque. The deflection force exists during the operation of the crankcase 100 and has an uncertain value. Therefore, the deflection torque can be controlled by changing the force arm corresponding to the deflection force; the exhaust speed close to the center of the cylinder is V1; the exhaust speed away from the center of the cylinder is V2, and the two speeds are different. The present application changes the size of the lever arm by changing the angle between the line 6 between the center of the cylinder hole and the center of the exhaust passage and the geometric symmetry axis 7 of the tongue spring, thereby reducing the deflection torque. In this embodiment, α=30°, h=L / 2, so the deflection torque is only half of the original torque, effectively improving the working reliability of the exhaust valve and avoiding the deflection torque affecting the service life of the exhaust valve.

[0025] like Figure 1 As shown, the exhaust valve assembly includes a limit plate 4, and the limit plate 4 presses and fixes the clamping part 3 to the outside of the valve plate 1, and the tongue spring 2 fits and covers the outlet of the exhaust channel. The tongue spring 2 includes a sealing part 21 and a spring plate part 22, and the sealing part 21 is connected to the clamping part 3 through the spring plate part 22, and the diameter of the sealing part 21 is larger than the diameter of the outlet of the exhaust channel. The limit plate 4 is used to limit the lift of the tongue spring 2, and the limit plate 4 is fixedly mounted on the valve plate 1 to lock the position of the clamping part 3. The spring plate part 22 bends to open the valve for exhaust when the sealing part 21 is impacted by the flow field, and the sealing part 21 is used to ensure that the exhaust channel is completely closed when no gas is discharged, thereby ensuring the sealing of the cylinder.

[0026] A reinforcing rib 5 is provided at the joint of the clamping part 3 and the spring plate part 22, and a clearance groove 12 is provided on the valve plate 1 corresponding to the reinforcing rib 5. The reinforcing rib 5 is provided along the width direction of the tongue spring 2. The two sides of the reinforcing rib 5 are smoothly transitioned to connect the clamping part 3 and the spring plate part 22 respectively.

[0027] The reinforcing ribs 5 are used to reduce stress concentration at the bend of the tongue reed 2 and reduce the possibility of fatigue failure of the tongue reed 2, while the rebate grooves 12 are used to ensure that the tongue reed 2 remains closed to the exhaust passage after resetting, and no gap will appear due to the interference of the reinforcing ribs 5. The reinforcing ribs 5 are used to strengthen the joint position of the spring plate portion 22 and the pressing portion 3 to ensure its anti-fatigue ability during the frequent bending of the tongue reed 2, and to connect the spring plate portion 22 and the pressing portion 3 in a smooth transition manner to avoid stress concentration at the joint and fatigue fracture.

[0028] Example 2

[0029] like Figure 4 As shown, the difference from Example 1 is that the line 6 connecting the center of the cylinder hole and the center of the exhaust channel coincides with the geometric symmetry axis of the tongue reed 2, and α=0°. When the line 6 connecting the center of the cylinder hole and the center of the exhaust channel coincides with the geometric symmetry axis 7 of the tongue reed, h=L*Sin0=0, and at this time M=(F1-F2)*L*Sin0=0, the deflection torque caused by the uneven flow field is completely eliminated, and the stress concentration caused by the deflection is avoided, thereby improving the working life of the exhaust valve. The structure is simple, the technical effect is easy to achieve, the cost is low and the effect is good.

[0030] In addition to the above-mentioned embodiments, within the scope disclosed in the claims and the specification of the present invention, the technical features of the present invention can be reselected and combined to form new embodiments, which can be achieved by those skilled in the art without creative work. Therefore, these embodiments that are not described in detail in the present invention should also be regarded as specific embodiments of the present invention and within the protection scope of the present invention.

Claims

1. An anti-deflection structure of a compressor exhaust valve, comprising a crankcase provided with a cylinder hole, an exhaust valve assembly provided on the crankcase, characterized in that: The exhaust valve assembly comprises a valve plate covering the cylinder hole, the valve plate is provided with an exhaust channel connected to the cylinder hole, the exhaust channel outlet is covered with a tongue reed, and the tail of the tongue reed is provided with a pressing portion connected to the valve plate; The deflection moment M borne by the tongue spring is (F1-F2)*h, F1 is the airflow pressure on the side of the tongue spring close to the center of the cylinder hole, F2 is the airflow pressure on the side of the tongue spring away from the center of the cylinder hole, and h is the distance from the deflection force formed by F1 and F2 to the center of the pressing part; wherein h=L*Sinα; Wherein, L is the distance between the center of the tongue reed and the center of the pressing portion; α is the angle between the line connecting the center of the cylinder hole and the center of the exhaust passage and the geometric symmetry axis of the tongue reed; wherein α≤30°.

2. The anti-deflection structure of a compressor exhaust valve according to claim 1, characterized in that: The connecting line between the center of the cylinder hole and the center of the exhaust passage coincides with the geometric symmetry axis of the tongue reed, α=0°.

3. The anti-deflection structure of a compressor exhaust valve according to claim 1, characterized in that: The exhaust valve assembly comprises a limit plate, and the limit plate presses and fixes the pressing part to the outer side of the valve plate, and the tongue spring fits and covers the outlet of the exhaust channel.

4. The anti-deflection structure of a compressor exhaust valve according to any one of claims 1 to 3, characterized in that: The tongue spring comprises a sealing portion and a spring plate portion, the sealing portion is connected to the pressing portion through the spring plate portion, and the diameter of the sealing portion is greater than the diameter of the exhaust passage outlet.

5. The anti-deflection structure of a compressor exhaust valve according to claim 4, characterized in that: A reinforcing rib is arranged at the joint of the pressing part and the elastic plate part, and a giving way groove is arranged on the valve plate corresponding to the reinforcing rib.

6. The anti-deflection structure of a compressor exhaust valve according to claim 5, characterized in that: The reinforcing ribs are arranged along the width direction of the tongue spring.

7. The anti-deflection structure of a compressor exhaust valve according to claim 5, characterized in that: The two sides of the reinforcing rib are smoothly transitioned to connect the pressing part and the spring plate part respectively.

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