Screw nut transmission mechanism and control method thereof

Abstract

The present invention provides a screw-nut transmission mechanism and a control method thereof, which relate to the field of mechanical transmission technology. The screw-nut transmission mechanism includes a first driving member, a transmission rod, a half nut, a screw, and a second driving member. The sides of the two half nuts that are close to each other are each provided with a semicircular groove that runs through the length direction of the screw. The ends of the two semicircular grooves that are away from each other are provided with internal threads that cooperate with the screw, and the ends of the two semicircular grooves that are close to each other are provided with a notch that makes way for the screw. The first driving member drives the transmission rod to drive the two half nuts to rotate so that the internal threads of the two half nuts cooperate with or separate from the screw. When the internal threads of the two half nuts gradually separate from the screw, the screw gradually rotates into the notch. The second driving member is used to drive the screw to rotate. The screw-nut transmission mechanism and the control method thereof can cooperate with or separate from the screw by driving the two half nuts to rotate. The assembly form is simple, the space occupied is small, and the control method is simple.

Description

Technical Field

[0001] The present invention relates to the technical field of mechanical transmission, and in particular to a screw-nut transmission mechanism and a control method thereof. Background Art

[0002] In the application of injection pumps, the coordination between the screw and the nut is an important structure for controlling the position accuracy and movement smoothness of the injection pump. Specifically, after the screw and the nut are coordinated, the position of the nut and the injection pump can be adjusted by driving the screw to rotate. After the injection pump moves into place, the screw and the nut are controlled to separate.

[0003] Existing nuts are composed of two halves. The relative positions of the two halves are controlled by rotating a square rod. The two halves mate to form a complete nut and engage with the screw. The two halves detach and release the screw. However, this screw-nut and nut structure currently occupies a large space, resulting in a significant amount of space occupied by the moving parts. Summary of the Invention

[0004] The purpose of the present invention includes providing a screw-nut transmission mechanism and a control method thereof, which can cooperate with or separate from the screw by driving the two half nuts to rotate, has a simple assembly form, occupies a small space, and has a simple control method.

[0005] The embodiments of the present invention can be implemented as follows:

[0006] In a first aspect, the present invention provides a screw-nut transmission mechanism, the screw-nut transmission mechanism comprising:

[0007] a first driving member;

[0008] A transmission rod, driven to rotate by the first driving member;

[0009] The two half nuts are respectively connected to opposite sides of the transmission rod and are arranged symmetrically with respect to the axis of the transmission rod. The two half nuts are staggered along the length direction of the screw rod. Semicircular grooves are provided on the sides of the two half nuts that are close to each other and pass through the length direction of the screw rod. The channel formed by the two semicircular grooves is used to accommodate the above-mentioned screw rod. The ends of the two semicircular grooves that are away from each other are provided with internal threads that cooperate with the screw rod, and the ends of the two semicircular grooves that are close to each other are provided with notches that make way for the screw rod. The transmission rod can drive the two half nuts to rotate so that the internal threads of the two half nuts can cooperate with or separate from the screw rod. When the internal threads of the two half nuts gradually separate from the screw rod, the screw rod gradually rotates into the notch.

[0010] The second driving member is used to drive the screw rod to rotate, and adjust the positions of the two half nuts on the screw rod when the internal threads of the two half nuts cooperate with the screw rod.

[0011] The beneficial effects of the screw-nut transmission mechanism and the control method thereof provided by the embodiments of the present invention include:

[0012] 1. By driving the transmission rod with the first driving member to rotate the two half nuts, the internal threads of the two half nuts can be engaged or separated with the screw rod, which is simple to assemble and occupies less space.

[0013] 2. The two half nuts will not move relative to each other. The rotation of the transmission rod can be used to control the engagement or separation of the half nuts and the screw rod, and the control method is simple.

[0014] In an optional embodiment, the two half nuts are an integrally formed structure, and the transmission rod is connected at the center position of the two half nuts.

[0015] In this way, the two half nuts do not need to be assembled, simplifying the structural form and production process.

[0016] In an optional embodiment, a clockwork spring is further provided at one end of the transmission rod connected to the half nut, and the clockwork spring is used to buffer the transmission of the transmission rod to the half nut.

[0017] In an optional embodiment, the notch is in the form of a chamfer with an angle of 30° to 60°.

[0018] In this way, the rotation angle required for the half nut is smaller, reducing the space occupied by the structure.

[0019] In an optional embodiment, the center lines of the internal threads in the two semicircular grooves coincide with each other, and the center lines of the two notches coincide with each other.

[0020] In this way, the two half nuts are tightly connected to the screw rod and the transmission is stable.

[0021] In an optional embodiment, a spacing groove section is further provided between the internal thread and the notch in the semicircular groove, and the spacing groove section is used to increase the distance between the internal thread and the notch.

[0022] In this way, the larger the distance between the internal thread and the notch, the smaller the rotation angle required for the half nut and the screw rod to be completely separated, which is beneficial to improving the adjustment efficiency and reducing the space occupied by the structure.

[0023] In an optional embodiment, in the semicircular groove, the major diameter of the internal thread is smaller than or equal to the inner diameter of the spacing groove segment, and the inner diameter of the spacing groove segment is smaller than or equal to the minimum inner diameter of the notch.

[0024] In this way, the diameter of the end from the end where the internal thread is set in the semicircular groove to the end where the notch is set can be gradually increased to further reduce the rotation angle required by the half nut.

[0025] In an optional embodiment, the screw-nut transmission mechanism further includes:

[0026] The housing is mounted on the two half nuts;

[0027] A return spring is arranged between the shell and the half nut. The return spring has an elastic force that pushes the half nut toward the screw rod so that the internal thread of the half nut cooperates with the screw rod.

[0028] In this way, in the process of the screw rod driving the half nut to move, although the screw rod will have a repulsive force on the half nut, the first driving member and the return spring both have the thrust to limit the half nut to cooperate with the screw rod, which is beneficial to improve the stability of the cooperation between the screw rod and the half nut, thereby improving the accuracy of the half nut position control.

[0029] In an optional embodiment, there are two return springs, and the two return springs are respectively arranged on two sides of the two half nuts that are away from each other.

[0030] In an optional embodiment, a receiving groove is provided on the half nut, and one end of the return spring is inserted into the receiving groove.

[0031] In this way, the stability of the connection between the return spring and the half nut can be improved.

[0032] In a second aspect, the present invention provides a control method for a screw-nut transmission mechanism. The control method is used to control the screw-nut transmission mechanism of the aforementioned embodiment. The control method includes:

[0033] Control the first driving member to drive the transmission rod to rotate in a first direction so that the internal threads of the two half nuts are engaged with the screw rod; control the second driving member to drive the screw rod to rotate so as to adjust the positions of the two half nuts on the screw rod;

[0034] The first driving member is controlled to drive the transmission rod to rotate in a second direction, which is opposite to the first direction, so that the internal threads of the two half nuts are separated from the screw rod.

[0035] In this way, the control method of the screw-nut transmission mechanism is simple and easy, which is conducive to quickly and accurately controlling the position of the half nut on the screw. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0037] Figure 1 A schematic structural diagram of a screw-nut transmission mechanism provided in an embodiment of the present invention;

[0038] Figure 2A schematic structural diagram of a screw-nut transmission mechanism (excluding the housing) provided in an embodiment of the present invention;

[0039] Figure 3 for Figure 2 Another perspective of

[0040] Figure 4 It is a structural diagram of two half nuts;

[0041] Figure 5 for Figure 4 Another perspective.

[0042] Icons: 1-housing; 2-first driving member; 3-transmission rod; 4-half nut; 41-accommodating groove; 42-semicircular groove; 421-internal thread; 422-spacer groove segment; 423-notch; 5-reset spring; 6-screw rod. DETAILED DESCRIPTION

[0043] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0044] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention as claimed, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort shall fall within the scope of protection of the present invention.

[0045] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0046] In the description of the present invention, it should be noted that if the terms "upper", "lower", "inside", "outside", etc. appear, the orientation or position relationship indicated is based on the orientation or position relationship shown in the accompanying drawings, or is the orientation or position relationship in which the product of the invention is usually placed when in use. It is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be understood as a limitation on the present invention.

[0047] In addition, the terms "first", "second", etc., if used, are merely used to distinguish and describe, and should not be understood as indicating or implying relative importance.

[0048] It should be noted that, in the absence of conflict, the features in the embodiments of the present invention may be combined with each other.

[0049] Please refer to Figures 1 to 3 This embodiment provides a screw 6 nut transmission mechanism that can be used to adjust the position of the injection pump and other components that require position adjustment.

[0050] Specifically, the screw 6 nut transmission mechanism includes a housing 1, a first driving member 2, a transmission rod 3, a half nut 4, a return spring 5, a screw 6 and a second driving member (not shown in the figure).

[0051] The first drive member 2, transmission rod 3, half nut 4, and return spring 5 can all be disposed within the housing 1. The first drive member 2 and the second drive member can be motors. The transmission rod 3 is driven for rotation by the first drive member 2. The two half nuts 4 are integrally formed, with the transmission rod 3 connected at the center of the two half nuts 4. The transmission rod 3 can drive the two half nuts 4 to rotate synchronously. In other embodiments, the two half nuts 4 can also be separate structures and assembled to the transmission rod 3.

[0052] Optionally, a clockwork spring is further provided at one end of the transmission rod 3 connected to the half nut 4, and the clockwork spring is used to buffer the transmission of the half nut 4 by the transmission rod 3. For example, when the transmission rod 3 drives the half nut 4 to rotate in a direction away from the screw rod 6, if the clockwork spring is not provided, if the transmission rod 3 rotates 45°, the half nut 4 and the screw rod 6 will be completely disengaged. In this embodiment, a clockwork spring is provided, and the transmission rod 3 can rotate more than 45° (for example, the transmission rod 3 is set to rotate 50°), and the clockwork spring is compressed at the same time; similarly, when the transmission rod 3 drives the half nut 4 to rotate in a direction close to the screw rod 6, the transmission rod 3 finally compresses the clockwork spring, and the clockwork spring presses the half nut 4 against the screw rod 6. In this way, the clockwork spring plays a buffering role in the transmission of the transmission rod 3 to the half nut 4. Even if the transmission rod 3 does not rotate into place, the clockwork spring can push the half nut 4 to rotate into place. Of course, in this embodiment, the transmission rod 3 can be set to over-rotate, that is, the rotation angle of the transmission rod 3 is set to be larger than the rotation angle of the transmission rod 3 when the clockwork spring is not set. The rotation angle of the transmission rod 3 refers to the angle required to rotate the half nut 4 into place.

[0053] The two half nuts 4 are sleeved on the screw rod 6, and the second driving member is used to drive the screw rod 6 to rotate. The injection pump or other components that need position adjustment are assembled on the half nuts 4.

[0054] During the process of the first driving member 2 controlling the rotation of the two half nuts 4, the internal threads 421 of the two half nuts 4 can be engaged with or separated from the screw rod 6. When the internal threads 421 of the two half nuts 4 are engaged with the screw rod 6, the second driving member drives the screw rod 6 to rotate to adjust the positions of the two half nuts 4 on the screw rod 6.

[0055] The return spring 5 is arranged between the housing 1 and the half nut 4. The return spring 5 has an elastic force that pushes the half nut 4 toward the screw rod 6 so that the internal thread 421 of the half nut 4 cooperates with the screw rod 6. There are two return springs 5, and the two return springs 5 ​​are respectively arranged on both sides of the two half nuts 4 that are away from each other. A receiving groove 41 is provided on the half nut 4, and one end of the return spring 5 is inserted into the receiving groove 41. In this way, the stability of the connection between the return spring 5 and the half nut 4 can be improved, and the return spring 5 can be prevented from moving on the half nut 4. Of course, the first driving member 2 has a greater driving force to drive the two half nuts 4 to compress the return spring 5, so that the half nuts 4 can be in contact with the screw rod 6.

[0056] During the process of the screw rod 6 and the half nut 4 cooperating and transmitting, the screw rod 6 exerts an extrusion force on the half nut 4 to separate the half nut 4. The function of the reset spring 5 is to improve the stability of the cooperation between the screw rod 6 and the half nut 4, thereby improving the accuracy of the position control of the half nut 4.

[0057] Please refer to Figures 3 to 5 The relative positions of the two half nuts 4 are as follows: the two half nuts 4 are respectively connected to the opposite sides of the transmission rod 3 and are arranged in a centrally symmetrical manner relative to the axis of the transmission rod 3. The two half nuts 4 are staggered along the length direction of the screw rod 6.

[0058] A semicircular groove 42 is formed on the side surfaces of the two half nuts 4 that are close to each other and passes through the length direction of the screw rod 6. The circular channel formed by splicing the two semicircular grooves 42 is used to accommodate the above-mentioned screw rod 6.

[0059] The ends of the two semicircular grooves 42 that are away from each other are provided with internal threads 421 that cooperate with the screw rod 6, and the ends of the two semicircular grooves 42 that are close to each other are provided with notches 423 that make way for the screw rod 6; the notches 423 are chamfered and have an angle of 30° to 60°. The center lines of the internal threads 421 in the two semicircular grooves 42 coincide with each other, and the center lines of the two notches 423 coincide with each other. The angle of the notches 423 is equal to the maximum rotation angle allowed by the half nut 4. The maximum rotation angle allowed by the half nut 4 is required to ensure that the internal threads 421 of the half nut 4 are completely disengaged from the screw rod 6, so that the rotation of the screw rod 6 does not change the position of the half nut 4.

[0060] The transmission rod 3 can drive the two half nuts 4 to rotate so that the internal threads 421 of the two half nuts 4 can be matched with or separated from the screw rod 6; for details, please refer to Figure 4 , two half nuts 4 along Figure 4 By rotating in the direction indicated by the middle arrow, the internal threads 421 of the two half nuts 4 can be matched with the screw rod 6; Figure 4The reverse rotation in the direction shown by the middle arrow can separate the internal threads 421 of the two half nuts 4 from the screw rod 6. When the internal threads 421 of the two half nuts 4 are gradually separated from the screw rod 6, the screw rod 6 gradually turns into the notch 423.

[0061] Please refer to Figure 5 A spacer section 422 is provided within the semicircular groove 42 between the internal thread 421 and the notch 423. This spacer section 422 increases the distance between the internal thread 421 and the notch 423 and may be a light hole. A larger distance between the internal thread 421 and the notch 423 reduces the required rotation angle for complete separation between the half nut 4 and the screw rod 6, improving adjustment efficiency and reducing the space occupied by the structure.

[0062] Within the semicircular groove 42, the major diameter of the internal thread 421 is less than or equal to the inner diameter of the spacing groove segment 422, and the inner diameter of the spacing groove segment 422 is less than or equal to the minimum inner diameter of the notch 423. In other words, the diameter of the semicircular groove 42 from the end where the internal thread 421 is provided to the end where the notch 423 is provided can gradually increase, further reducing the required rotation angle of the half nut 4.

[0063] The embodiment of the present invention further provides a control method for a screw 6 nut transmission mechanism, the control method is used to control the screw 6 nut transmission mechanism of the aforementioned embodiment, and the control method includes:

[0064] On the one hand, when it is necessary to adjust the position of the half nut 4 on the screw rod 6, first, control the first driving member 2 to drive the transmission rod 3 to rotate in the first direction so that the internal threads 421 of the two half nuts 4 cooperate with the screw rod 6; then, control the second driving member to drive the screw rod 6 to rotate to adjust the position of the two half nuts 4 on the screw rod 6.

[0065] On the other hand, when there is no need to adjust the position of the half nut 4 on the screw rod 6, first, control the first driving member 2 to drive the transmission rod 3 to rotate in the second direction, which is opposite to the first direction, so that the internal threads 421 of the two half nuts 4 are separated from the screw rod 6; then, the second driving member can be controlled to stop; if the second driving member has stopped before the half nut 4 rotates, the operation is completed.

[0066] The beneficial effects of the screw 6 nut transmission mechanism and the control method thereof provided by the embodiments of the present invention include:

[0067] 1. By driving the transmission rod 3 with the first driving member 2 to rotate the two half nuts 4, the internal threads 421 of the two half nuts 4 can be engaged or disengaged with the screw rod 6. The assembly form is simple and takes up little space.

[0068] 2. The two half nuts 4 do not move relative to each other. The rotation of the transmission rod 3 can be used to control the engagement or separation of the half nuts 4 and the screw rod 6. The control method is simple;

[0069] 3. In the process of the screw rod 6 driving the half nut 4 to move, although the screw rod 6 will have a repulsive force on the half nut 4, the first driving member 2 and the return spring 5 both have the thrust to limit the half nut 4 to cooperate with the screw rod 6, which is beneficial to improve the stability of the cooperation between the screw rod 6 and the half nut 4, thereby improving the accuracy of the position control of the half nut 4.

[0070] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. A screw-nut transmission mechanism, characterized in that: The screw nut transmission mechanism includes: a first driving member (2); A transmission rod (3) is driven to rotate by the first driving member (2); Two half nuts (4) are respectively connected to the opposite sides of the transmission rod (3) and are arranged in a central symmetrical manner relative to the axis of the transmission rod (3). The two half nuts (4) are staggered along the length direction of the screw rod (6). The sides of the two half nuts (4) close to each other are provided with a semicircular groove (42) penetrating along the length direction of the screw rod (6). The channel formed by splicing the two semicircular grooves (42) is used to accommodate the above-mentioned screw rod (6). The ends of the two semicircular grooves (42) far away from each other are provided with a The inner thread (421) of the screw rod (6) is matched, and a notch (423) is provided at one end of the two semicircular grooves (42) close to each other to make way for the screw rod (6); the transmission rod (3) can drive the two half nuts (4) to rotate, so that the inner threads (421) of the two half nuts (4) are matched with or separated from the screw rod (6); when the inner threads (421) of the two half nuts (4) are gradually separated from the screw rod (6), the screw rod (6) gradually rotates into the notch (423); The second driving member is used to drive the screw rod (6) to rotate, and adjust the positions of the two half nuts (4) on the screw rod (6) when the internal threads (421) of the two half nuts (4) cooperate with the screw rod (6).

2. The screw-nut transmission mechanism according to claim 1, characterized in that: The two half nuts (4) are an integrally formed structure, and the transmission rod (3) is connected to the center position of the two half nuts (4); one end of the transmission rod (3) connected to the half nuts (4) is also provided with a spring, and the spring is used to buffer the transmission of the transmission rod (3) to the half nuts (4).

3. The screw-nut transmission mechanism according to claim 1, characterized in that: The notch (423) is in the form of a chamfer, and the angle is 30° to 60°.

4. The screw-nut transmission mechanism according to claim 1, characterized in that: The center lines of the internal threads (421) in the two semicircular grooves (42) coincide with each other, and the center lines of the two notches (423) coincide with each other.

5. The screw-nut transmission mechanism according to claim 1, characterized in that: In the semicircular groove (42), a spacing groove section (422) is further provided between the internal thread (421) and the notch (423), and the spacing groove section (422) is used to increase the distance between the internal thread (421) and the notch (423).

6. The screw-nut transmission mechanism according to claim 5, characterized in that: In the semicircular groove (42), the major diameter of the internal thread (421) is smaller than or equal to the inner diameter of the spacing groove section (422), and the inner diameter of the spacing groove section (422) is smaller than or equal to the minimum inner diameter of the notch (423).

7. The screw-nut transmission mechanism according to claim 1, characterized in that: The screw nut transmission mechanism also includes: A housing (1) is provided on the two half nuts (4); A return spring (5) is provided between the housing (1) and the half nut (4), and the return spring (5) has an elastic force for pushing the half nut (4) toward the screw rod (6), so that the internal thread (421) of the half nut (4) is matched with the screw rod (6).

8. The screw-nut transmission mechanism according to claim 7, characterized in that: The number of the return springs (5) is two, and the two return springs (5) are respectively arranged on two sides of the two half nuts (4) that are away from each other.

9. The screw-nut transmission mechanism according to claim 8, characterized in that: The half nut (4) is provided with a receiving groove (41), and one end of the return spring (5) is inserted into the receiving groove (41).

10. A control method for a screw-nut transmission mechanism, characterized in that: The control method is used to control the screw-nut transmission mechanism according to claim 1, and the control method includes: Controlling the first driving member (2) to drive the transmission rod (3) to rotate in a first direction so that the internal threads (421) of the two half nuts (4) cooperate with the screw rod (6); controlling the second driving member to drive the screw rod (6) to rotate so as to adjust the positions of the two half nuts (4) on the screw rod (6); The first driving member (2) is controlled to drive the transmission rod (3) to rotate in a second direction, the second direction being opposite to the first direction, so that the internal threads (421) of the two half nuts (4) are separated from the screw rod (6).

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