Valve needle assembly, machining method and machining equipment of valve needle assembly and electronic expansion valve

Abstract

The invention discloses a valve needle assembly and a machining method, machining equipment and an electronic expansion valve thereof.The valve needle assembly comprises a valve needle (11), a lead screw (12) and a rolling part (13), the valve needle (11) and the lead screw (12) are axially connected in a limiting mode, the axially opposite end walls of the valve needle (11) and the lead screw (12) are provided with abutting parts (A), the rolling part (13) is movably arranged between the valve needle (11) and the lead screw (12) and abuts against the abutting parts (A), and the rolling part (13) is movably connected with the valve needle (11) and the lead screw (12). The hardness of the abutting part (A) in the valve needle (11) is larger than the hardness of other parts in the valve needle (11), and the hardness of the abutting part (A) in the lead screw (12) is larger than the hardness of other parts in the lead screw (12). According to the invention, each abutting part (A) is independently hardened, so that the abrasion and deformation of the abutting parts after long-term operation are reduced, and the overall processing difficulty and processing cost of parts are not increased.

Description

Technical Field

[0001] The present invention relates to the technical field of refrigeration control, and particularly relates to a valve needle assembly, a processing method thereof, processing equipment, and an electronic expansion valve. Background Art

[0002] An electronic expansion valve is commonly used in a refrigeration system to adjust the flow rate of refrigerant. The electronic expansion valve includes a valve needle assembly, and the valve needle assembly includes a lead screw and a valve needle. The lead screw is connected to the valve needle, and the valve needle can approach or move away from the valve port. Since the various components of the valve needle assembly need to cooperate with each other, it is found in practice that during long-term operation, abnormal wear and deformation are likely to occur between the lead screw and the core body, affecting the mating dimensions and further affecting the flow rate adjustment accuracy.

[0003] Therefore, how to reduce the abnormal wear and deformation of the abutting portion is a technical problem that needs to be urgently solved by those skilled in the art. Summary of the Invention

[0004] The purpose of the present invention is to provide a valve needle assembly to reduce the abnormal wear and deformation of the abutting portion.

[0005] To solve the above technical problems, the present invention provides a valve needle assembly, including a valve needle, a lead screw, and a rolling member. The valve needle and the lead screw are axially limited and connected. An abutting portion is provided on the end walls of the valve needle and the lead screw that are axially opposite to each other. The rolling member is movably arranged between the valve needle and the lead screw and abuts against the abutting portion. The hardness of the abutting portion in the valve needle is greater than the hardness of other parts in the valve needle, and the hardness of the abutting portion in the lead screw is greater than the hardness of other parts in the lead screw.

[0006] For the valve needle assembly of the present invention, the abutting portion in contact with the rolling member is separately hardened, only the hardness of the abutting portion is increased, the wear and deformation of the abutting portion after long-term operation are reduced, and the flow rate adjustment accuracy is ensured. At the same time, the lead screw and the valve needle as a whole can still be made of the original material with a lower hardness, without increasing the processing difficulty of the parts; nor is it necessary to adopt the method of overall hardening after processing the lead screw and the valve needle, simplifying the processing process, improving the processing efficiency, and reducing the processing cost.

[0007] Optionally, the hardness of the abutting portion is equivalent to the hardness of the rolling member.

[0008] Optionally, the shape of the abutting portion matches the shape of the rolling member, and the diameter of the abutting portion is not less than the diameter of the rolling member.

[0009] Optionally, the roughness of the abutting portion is not greater than the roughness of other parts in the valve needle or the lead screw.

[0010] The present invention also provides a processing method for a valve needle assembly, applicable to the foregoing valve needle assembly, and characterized by including the following step A:

[0011] A butt - joint part is machined on the corresponding end wall of the valve needle or the lead screw, and then the butt - joint part is rotationally extruded by an extruding part; or, the butt - joint part is rotationally extruded on the corresponding end wall of the valve needle or the lead screw by the extruding part.

[0012] The processing method of the valve needle assembly of the present invention is applicable to the aforementioned valve needle assembly, so it has the same technical effects as the aforementioned valve needle assembly, which will not be elaborated here.

[0013] Optionally, before the step A, the processing of the lead screw further includes the following steps:

[0014] First, a connecting groove at the corresponding end of the lead screw is machined to obtain a rough - machined workpiece of the lead screw;

[0015] The processing of the lead screw further includes the following step B:

[0016] First, the outer shape of the lead screw is machined, and then the thread of the lead screw is machined;

[0017] The step B is before or after the step A.

[0018] Optionally, before the step A, the processing of the valve needle further includes the following steps:

[0019] First, a connecting groove of the valve needle is machined to obtain a rough - machined workpiece of the valve needle.

[0020] The processing of the valve needle further includes the following step C:

[0021] Machine the outer shape of the valve needle;

[0022] The step C is before or after the step A.

[0023] The present invention also provides a processing device for a valve needle assembly, which is used to process the aforementioned valve needle assembly. The device includes an extruding part, and the extruding part has an extrusion ball head. The shape of the extrusion ball head matches the shape of the rolling part, the diameter of the extrusion ball head is not less than the diameter of the rolling part, and the extrusion ball head is used to extrude the butt - joint part or extrude and form the butt - joint part.

[0024] The processing device of the present invention is used to process the aforementioned valve needle assembly, so it has the same technical effects as the aforementioned valve needle assembly, which will not be elaborated here.

[0025] Optionally, a smooth extrusion surface is formed on the outer surface of the extrusion ball head.

[0026] The present invention also provides an electronic expansion valve, which includes a valve seat with a valve port, and also includes the aforementioned valve needle assembly. The valve needle assembly can perform axial lifting motion to adjust the opening degree of the valve port.

[0027] The electronic expansion valve of the present invention includes the aforementioned valve needle assembly, and thus has the same technical effects as the aforementioned valve needle assembly, which will not be elaborated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic structural diagram of a specific embodiment of the valve needle assembly provided by the present invention;

[0029] Figure 2 is Figure 1 a schematic structural diagram of the valve needle in the valve needle assembly;

[0030] Figure 3 is Figure 1 a schematic structural diagram of the lead screw in the valve needle assembly;

[0031] Figure 4 is Figure 2 a schematic structural diagram of the valve needle at a second angle;

[0032] Figure 5 is Figure 4 a sectional view of;

[0033] Figure 6 is Figure 2 a schematic structural diagram of the valve needle at a third angle;

[0034] Figure 7 is Figure 3 a schematic structural diagram of the lead screw at a second angle;

[0035] Figure 8 is Figure 3 a schematic structural diagram of the lead screw at a third angle;

[0036] Figure 9 is Figure 8 a sectional view of;

[0037] Figure 10 is a schematic structural diagram of the rough machined part of the lead screw;

[0038] Figure 11 is Figure 10 a schematic structural diagram of the rough machined part of the lead screw at a second angle;

[0039] Figure 12 is Figure 10 a sectional view of;

[0040] Figure 13 is the first state diagram in the step of extruding the abutting part of the rough machined part of the lead screw;

[0041] Figure 14 is the second state diagram in the step of extruding the abutting part of the rough machined part of the lead screw;

[0042] Figure 15 Schematic diagram of the structure of the machined part of the lead screw's outer shape

[0043] Figure 16 is Figure 15 Schematic diagram of the structure of the machined part of the lead screw's outer shape from a second angle

[0044] Figure 17 is Figure 16 the cross-sectional view of

[0045] Figure 18 Schematic diagram of the structure of the initial lead screw

[0046] Figure 19 is Figure 18 Another schematic diagram of the structure of the initial lead screw

[0047] Figure 20 is Figure 18 Schematic diagram of the structure of the initial lead screw from a second angle

[0048] Figure 21 is Figure 18 The first cross-sectional view of the initial lead screw

[0049] Figure 22 is Figure 18 The second cross-sectional view of the initial lead screw

[0050] Figure 23 The state diagram during the step of extruding the abutting part of the initial lead screw

[0051] Figure 24 Schematic diagram of the structure of the rough machined part of the valve needle

[0052] Figure 25 is Figure 18 the cross-sectional view of

[0053] Figure 26 The first state diagram during the step of extruding the abutting part of the rough machined part of the valve needle

[0054] Figure 27 The second state diagram during the step of extruding the abutting part of the rough machined part of the valve needle

[0055] Figure 28 Schematic diagram of the structure of the initial valve needle

[0056] Figure 29 is Figure 28 The cross-sectional view of the initial valve needle

[0057] Figure 30 is Figure 28 Schematic diagram of the structure of the initial valve needle from a second angle

[0058] Figure 31 State diagram in the step of pressing the abutting part for the initial valve needle;

[0059] Figure 32 Structural schematic diagram of a specific embodiment of the electronic expansion valve provided by the present invention;

[0060] Among them, Figures 1 - 32 The description of the reference numerals in the drawings is as follows:

[0061] 1-valve needle assembly; 11-valve needle; 11A-rough machining part of the valve needle; 11B-initial valve needle; 12-screw rod; 12A-rough machining part of the screw rod; 12B-profile machining part of the screw rod; 12C-initial screw rod; 13-rolling element; A-abutting part;

[0062] 2-valve seat; 3-housing; 4-rotor; 5-nut;

[0063] 01-pressing part; 011-pressing ball head. Specific embodiments

[0064] In order to enable those skilled in the art to better understand the technical solutions of the present invention, the present invention will be further described in detail below with reference to the drawings and specific embodiments.

[0065] As used herein, "a plurality" generally means more than two; and when "a plurality" is used to represent the quantity of several components, it does not represent the mutual relationship in quantity of these components.

[0066] In this article, the Figure 13 , the Figure 23 , the Figure 31 The arrow shown in the figure indicates the moving direction of the pressing part 01.

[0067] Please refer to Figures 1 - 3 , Figure 1 Structural schematic diagram of a specific embodiment of the valve needle assembly provided by the present invention; Figure 2 For Figure 1 Structural schematic diagram of the valve needle in the valve needle assembly; Figure 3 For Figure 1 Structural schematic diagram of the screw rod 12 in the valve needle assembly.

[0068] The present invention provides a valve needle assembly 1, including a valve needle 11, a screw rod 12 and a rolling element 13. The valve needle 11 and the screw rod 12 are axially limited and connected, that is, the two can move synchronously along the axis. The end walls of the valve needle 11 and the screw rod 12 facing each other axially are provided with an abutting part A. The rolling element 13 is movably arranged between the valve needle 11 and the screw rod 12 and abuts against the abutting part A. The hardness of the abutting part A in the valve needle 11 is greater than the hardness of other parts in the valve needle 11, and the hardness of the abutting part A in the screw rod 12 is greater than the hardness of other parts in the screw rod 12.

[0069] For the valve needle assembly 1 of the present invention, the abutting portion A in contact with the rolling member 13 is hardened separately, only the hardness of the abutting portion A is increased, the wear and deformation of the abutting portion A after long-term operation are reduced, and the flow rate adjustment accuracy is ensured. At the same time, the lead screw 12 and the valve needle 11 as a whole can still be made of the original material with relatively low hardness, without increasing the processing difficulty of the parts; nor is it necessary to adopt the method of overall quenching after processing for the lead screw 12 and the valve needle 11, which simplifies the processing process, improves the processing efficiency, and reduces the processing cost.

[0070] Among them, for the separate hardening of the abutting portion A, it can be selected to perform rotary extrusion on the corresponding end walls of the lead screw 12 and the valve needle 11 through an extruding member, while processing the size of the abutting portion A, realizing extrusion cold working hardening, and improving the hardness of the abutting portion A; or, in the part cutting process, the abutting portion A can be processed on the corresponding end walls of the lead screw 12 and the valve needle 11, and after processing, the abutting portion A is extruded again through an extruding member to realize extrusion cold working hardening and improve the hardness of the abutting portion A.

[0071] Among them, the shape of the abutting portion A matches the shape of the rolling member 13, that is, the abutting portion A is designed by copying the shape of the rolling member 13, and the diameter of the abutting portion A is not less than the diameter of the rolling member 13.

[0072] In order to further reduce the abnormal wear and deformation of the abutting portion A and ensure the flow rate adjustment accuracy, the hardness of the abutting portion A should be equivalent to the hardness of the rolling member 13.

[0073] When it is said that "the hardness of the abutting portion A is equivalent to the hardness of the rolling member 13", in an ideal state, the hardness value of the abutting portion A is equal to the hardness value of the rolling member 13. At this time, the abutting portion A can minimize abnormal wear and deformation; but in actual applications, affected by various factors, such as the hardness of the material itself, processing errors, etc., there will inevitably be a certain error between the hardness of the abutting portion A and the hardness of the rolling member 13. Therefore, when the hardness of the abutting portion A is equivalent to the hardness of the rolling member 13, it should be ensured that the hardness difference between the abutting portion A and the rolling member 13 does not exceed 10, and preferably the hardness difference does not exceed 5.

[0074] In practice, to make the hardness of the abutting portion A equivalent to the hardness of the rolling member 13, the materials of the lead screw 12 and the valve needle 11 themselves also need to be selected. The hardness of the materials of the lead screw 12 and the valve needle 11 themselves can be lower than but close to the hardness of the rolling member 13.

[0075] In addition, the roughness of the abutting portion A should not be greater than the roughness of other parts of the valve needle 11 or the lead screw 12, so as to reduce the friction between the rolling member 13 and the abutting portion A, ensure that the rolling member 13 will not rotate under the action of the lead screw 12, and avoid torque transmission between the lead screw 12 and the valve needle 11.

[0076] The present invention also provides a processing method for a valve needle assembly, which is applicable to the aforementioned valve needle assembly 1, and is characterized in that it includes the following step A:

[0077] Process the abutting portion A on the corresponding end wall of the valve needle 11 or the lead screw 12, and then rotate and extrude the abutting portion A through the extruding member 01; or, rotate and extrude the abutting portion A on the corresponding end wall of the valve needle 11 or the lead screw 12 through the extruding member 01.

[0078] The processing method of the valve needle assembly of the present invention is applicable to the aforementioned valve needle assembly 1, so it has the same technical effects as the aforementioned valve needle assembly 1, which will not be elaborated here.

[0079] Furthermore, in the present invention, before step A, the processing of the lead screw 12 further includes the following steps:

[0080] First, process the connecting groove at the corresponding end of the lead screw 12. The connecting groove is used for axially limiting and connecting with the valve needle 11, thereby obtaining the rough machining part 12A of the lead screw, as Figures 10 - 12 shown;

[0081] As Figures 13 - 14 shown, rotate and extrude through the extruding member 01 on the basis of the rough machining part 12A of the lead screw to obtain the abutting portion A.

[0082] The processing of the lead screw 12 further includes the following step B:

[0083] Process the outer shape of the lead screw 12 to obtain the outer shape machining part 12B of the lead screw, as Figures 15 - 17 shown; then, on the basis of the outer shape machining part 12B of the lead screw, process the thread of the lead screw 12, as Figure 3 、 Figure 9 shown.

[0084] It can be seen that in the above processing method, step B is after step A, that is, first rotate and extrude to obtain the abutting portion A, and then process the outer shape and thread of the lead screw 12. It can be understood that in actual application, it is also feasible that step B is after step A. After processing the outer shape and thread of the lead screw 12, then rotate and extrude to obtain the abutting portion A.

[0085] As Figures 18 - 22 shown, after processing the outer shape and thread of the lead screw 12, obtain the initial lead screw 12C;

[0086] As Figure 23 shown, on the basis of the initial lead screw 12C, rotate and extrude to obtain the abutting portion A to form the final lead screw 12.

[0087] Furthermore, in the present invention, before step A, the processing of the valve needle 11 further includes the following steps:

[0088] First, process the connection groove of the valve needle 11 to obtain the rough machining part 11A of the valve needle, as Figure 24 and Figure 25 shown;

[0089] As Figure 26 and Figure 27 shown, rotate and extrude on the basis of the rough machining part 11A of the valve needle to obtain the abutting part A;

[0090] The processing of the valve needle 11 further includes the following step C:

[0091] Process the outer shape of the valve needle 11 to obtain the final valve needle 11, as Figure 2 , Figures 4 - 6 shown.

[0092] It can be seen that in the above processing method, step C is after step A, that is, first rotate and extrude on the basis of the rough machining part 11A of the valve needle to obtain the abutting part A, and then process the outer shape of the valve needle 11. It can be understood that in practical applications, it is also feasible for step C to be before step A. After processing the outer shape of the valve needle 11, rotate and extrude to obtain the abutting part A.

[0093] As Figures 28 - 30 shown, after processing the outer shape of the valve needle 11, obtain the initial valve needle 11B;

[0094] As Figure 31 shown, on the basis of the initial valve needle 11B, rotate and extrude to obtain the abutting part A to form the final valve needle 11.

[0095] Please continue to refer to Figure 27 , the present invention also provides a processing device for a valve needle assembly for processing the aforementioned valve needle assembly 1. The processing device includes an extrusion member 01. The extrusion member 01 has an extrusion ball head 011. The shape of the extrusion ball head 011 matches the shape of the rolling member 13, and the diameter of the extrusion ball head 011 is not less than the diameter of the rolling member 13.

[0096] The processing device of the present invention is used to process the aforementioned valve needle assembly 1. Therefore, it has the same technical effects as the aforementioned valve needle assembly 1 and will not be elaborated here.

[0097] Among them, the outer surface of the extrusion ball head 011 forms the extrusion surface. In order to make the roughness of the abutting part A processed on the valve needle 11 or the lead screw 12 not greater than the roughness of other parts of the valve needle 11 or the lead screw 12, the extrusion surface should be smooth to reduce the friction between the rolling member 13 and the abutting part A, ensure that the rolling member 13 will not rotate under the action of the lead screw 12, and avoid torque transmission between the lead screw 12 and the valve needle 11.

[0098] Please refer to Figure 32 , Figure 32The structural schematic diagram of a specific embodiment of the electronic expansion valve provided by the present invention.

[0099] The present invention also provides an electronic expansion valve, which includes a valve seat 2. The valve seat 2 has a valve port, and further includes the aforementioned valve needle assembly 1. The valve needle assembly 1 can perform axial lifting movement to adjust the opening degree of the valve port.

[0100] The electronic expansion valve of the present invention includes the aforementioned valve needle assembly 1. Therefore, it has the same technical effects as the aforementioned valve needle assembly 1, which will not be elaborated here.

[0101] Among them, the electronic expansion valve further includes a housing 3, a rotor 4 and a nut 5. The valve seat 2 and the housing 3 are fixed. An inner cavity of the electronic expansion valve is formed between the valve seat 2 and the housing 3. The valve needle assembly 1, the rotor 4 and the nut 5 are all arranged inside the inner cavity. The rotor 4 is connected to the lead screw 12 in the valve needle assembly 1. The rotor 4 can rotate under the driving action of a driving coil (not shown in the figure) to drive the lead screw 12 to rotate together. The nut 5 and the lead screw 12 have a matching thread pair. The nut 5 is directly or indirectly fixed to the valve seat 2. When the lead screw 12 rotates, under the action of the thread pair, the lead screw 12 simultaneously performs axial lifting movement, driving the valve needle 11 in the valve needle assembly 1 to synchronously perform axial lifting movement to adjust the opening degree of the valve port, and further adjust the flow rate of the refrigerant.

[0102] The above has introduced in detail a valve needle assembly, its processing method, processing equipment and electronic expansion valve provided by the present invention. Specific examples are used in this article to elaborate the principle and implementation manner of the present invention. The description of the above embodiments is only used to help understand the method and its core idea of the present invention. It should be pointed out that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and modifications can still be made to the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. A valve needle assembly, characterized in that, It includes a valve needle (11), a lead screw (12) and a rolling element (13). The valve needle (11) and the lead screw (12) are axially limited and connected. The end walls of the valve needle (11) and the lead screw (12) facing each other axially are provided with abutting portions (A). The rolling element (13) is movably arranged between the valve needle (11) and the lead screw (12) and abuts against the abutting portion (A). The hardness of the abutting portion (A) in the valve needle (11) is greater than the hardness of other parts of the valve needle (11), and the hardness of the abutting portion (A) in the lead screw (12) is greater than the hardness of other parts of the lead screw (12).

2. The valve needle assembly according to claim 1, wherein, The hardness of the abutting portion (A) is equivalent to the hardness of the rolling element (13).

3. The valve needle assembly according to claim 1, wherein The shape of the abutting portion (A) matches the shape of the rolling element (13), and the diameter of the abutting portion (A) is not less than the diameter of the rolling element (13).

4. The valve needle assembly according to claim 1, wherein, The roughness of the abutting portion (A) is not greater than the roughness of other parts of the valve needle (11) or the lead screw (12).

5. A processing method for a valve needle assembly, applicable to the valve needle assembly according to any one of claims 1-4, characterized in that, It includes the following step A: Machine the abutting portion (A) on the corresponding end wall of the valve needle (11) or the lead screw (12), and then rotate and extrude the abutting portion (A) through an extruding member (01); or, rotate and extrude the abutting portion (A) on the corresponding end wall of the valve needle (11) or the lead screw (12) through the extruding member (01).

6. The processing method of the valve needle assembly according to claim 5, characterized in that Before the step A in the machining of the lead screw (12), the following steps further include: First machine the connecting groove at the corresponding end of the lead screw (12) to obtain a blank machining part (12A) of the lead screw; The machining of the lead screw (12) further includes the following step B: First machine the outer shape of the lead screw (12), and then machine the thread of the lead screw (12). The step B is before or after the step A.

7. The processing method of the valve needle assembly according to claim 5, characterized in that, Before the step A in the machining of the valve needle (11), the following steps further include: First machine the connecting groove of the valve needle (11) to obtain a blank machining part (11A) of the valve needle, The machining of the valve needle (11) further includes the following step C: Machine the outer shape of the valve needle (11); The step C is before or after the step A.

8. A processing device for a valve needle assembly, which is used to process the valve needle assembly according to any one of claims 1-4, characterized in that, It includes an extruding member (01). The extruding member (01) has an extruding ball head (011). The shape of the extruding ball head (011) matches the shape of the rolling element (13). The diameter of the extruding ball head (011) is not less than the diameter of the rolling element (13). The extruding ball head (011) is used to extrude the machined abutting portion (A) or extrude and form the abutting portion (A).

9. The processing equipment for the valve needle assembly according to claim 8, characterized in that, The outer surface of the extruding ball head (011) forms an extruding surface, and the extruding surface is a smooth curved surface.

10. An electronic expansion valve, characterized in that, It includes a valve seat (2). The valve seat (2) has a valve port. It also includes the valve needle assembly according to any one of claims 1-4. The valve needle assembly (1) can perform axial lifting movement to adjust the opening degree of the valve port.

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