DC contactor

Abstract

The utility model discloses a DC contactor, comprising: an outer shell, a static contact, a moving contact piece, a push rod group and an electromagnetic mechanism, wherein the moving contact piece is movably mounted on the push rod group and is applied with an elastic force in the direction of the static contact by a contact spring of the push rod group, and the electromagnetic mechanism is used to drive the push rod group to push the moving contact piece to abut against the static contact, and the moving distance of the push rod group is greater than the moving distance of the moving contact piece, so that the contact spring is further compressed; wherein the further compressed amount of the contact spring is M millimeters; the push rod group comprises an elastic member, and the elastic member is used to apply an elastic force in the direction of the static contact to the moving contact piece after the further compressed amount of the contact spring is N millimeters, and 0<N<M. The utility model can improve the short-circuit resistance of the DC contactor, and can effectively prevent the secondary pull-in phenomenon, and improve the working stability and life of the DC contactor.

Description

Technical Field

[0001] The utility model relates to the technical field of electric control devices, in particular to a DC contactor. Background Art

[0002] The DC contactors currently on the market generally include an electromagnetic part, a moving part, a contact part, an arc extinguishing part and an installation part. The electromagnetic part is responsible for converting electrical energy into kinetic energy, the moving part is responsible for the connection between the electromagnetic part and the contact part, the arc extinguishing part is responsible for extinguishing the arc generated when the contact part is disconnected, the installation part is responsible for providing the customer with the assembly position, and the contact part is responsible for the execution of the contactor's on and off.

[0003] Among them, the moving contact piece of the contact part is installed on the push rod of the moving part and is exerted with elastic force by a spring. In the process of the electromagnetic part driving the moving part to drive the moving contact piece to move, the moving distance of the push rod is greater than the moving distance of the moving contact piece, so that the moving part moves over the travel compared to the moving contact piece. At this time, the spring is further compressed, and the elastic force exerted by the spring on the moving contact piece makes the moving contact piece reliably rest against the static contact.

[0004] With the promotion of DC contactor applications in the energy storage field, the short-circuit resistance requirements for household energy storage have also been put on the agenda. Due to the small current and small product size of household energy storage, it is impossible to add short-circuit resistance structures, and thus it is impossible to provide additional compensation force. When the product is short-circuited, it is easy to be repelled by the electric repulsion force, causing the product to explode or catch fire.

[0005] The existing solution is generally to directly increase the spring K value; Figure 1 As shown, when the spring K value is not increased, the elastic force on the moving contact piece is shown as curve ①, and the elastic force on the moving contact piece after the spring K value is increased is shown as curve ②. The elastic force curve (curve ②) of the spring after the K value is increased is easy to touch the suction curve (curve ④) of the electromagnetic part, and even worse, the elastic force curve (curve ②) intersects with the suction curve (curve ④), thereby causing the moving part to produce a secondary attraction phenomenon, resulting in unstable operation and short life of the DC contactor. Therefore, it is necessary to improve the existing technology to overcome the defects in the existing technology. Summary of the invention

[0006] The problem to be solved by the utility model is to provide a DC contactor to overcome the defects of the existing DC contactor that secondary attraction is easy to occur, resulting in unstable operation and short service life.

[0007] The technical solution adopted by the utility model to solve the technical problem is: a DC contactor, comprising:

[0008] outer shell;

[0009] A stationary contact, the stationary contact being fixed to the outer shell;

[0010] A moving contact piece, the moving contact piece is accommodated in the outer shell and arranged opposite to the stationary contact;

[0011] and a push rod group and an electromagnetic mechanism both accommodated in the outer shell, the movable contact piece being movably mounted on the push rod group and being exerted with an elastic force in the direction of the stationary contact by a contact spring of the push rod group, the electromagnetic mechanism being used to drive the push rod group to push the movable contact piece to abut against the stationary contact, and the moving distance of the push rod group being greater than the moving distance of the movable contact piece, so that the contact spring is further compressed; wherein the contact spring is further compressed by an amount of M millimeters;

[0012] The push rod assembly includes an elastic member, and the elastic member is used to apply an elastic force on the moving contact piece toward the static contact after the contact spring is further compressed to a compression amount of N millimeters; wherein 0<N<M.

[0013] As a further improvement of the present invention, the push rod assembly further includes a push rod and a support sheet arranged on the push rod, and the elastic member is arranged between the moving contact sheet and the support sheet.

[0014] As a further improvement of the present invention, the elastic member is fixed to the bottom of the movable contact piece through a bracket, and in a natural state, the lower end of the elastic member and the support piece do not contact each other, and the distance between the two is N millimeters.

[0015] As a further improvement of the present invention, the bracket is made of plastic material, and the upper end of the elastic member is integrally injection-molded in the bracket.

[0016] As a further improvement of the present invention, the bracket is provided with a main body and two symmetrical snap-in parts extending upward from both sides of the main body, the main body is abutted against the bottom surface of the moving contact piece, and the two snap-in parts are snap-in on both sides of the moving contact piece respectively.

[0017] As a further improvement of the present invention, the movable contact piece can be slidably mounted on the upper end of the push rod, and the push rod is located above the movable contact piece and fixed with a limiting member, the middle part of the main body is provided with an avoidance hole for the push rod to pass through, the lower end of the contact spring elastically abuts against the support piece, and the upper end of the contact spring passes through the avoidance hole and elastically abuts against the bottom surface of the movable contact piece;

[0018] In a natural state, the movable contact piece is stopped upward at the bottom of the limiting member by the elastic force of the contact spring.

[0019] As a further improvement of the present invention, the elastic member is a spring which is sleeved on the outside of the contact spring.

[0020] As a further improvement of the present invention, the lower end of the elastic member is fixedly connected to the supporting sheet, and in a natural state, the upper end of the elastic member and the moving contact sheet do not contact each other, and the distance between the two is N millimeters.

[0021] As a further improvement of the present invention, the elastic member is any one or a combination of a spring, a leaf spring, and an elastic washer.

[0022] As a further improvement of the present invention, the M satisfies the formula: 1≤M≤3; and the N satisfies the formula: 0.5≤N≤2.5.

[0023] The beneficial effects of the utility model are as follows: the utility model provides a DC contactor, in which a contact spring and an elastic member are arranged on a push rod group, and the elastic member and the contact spring jointly provide pressure for a moving contact piece, so that the moving contact piece stably and reliably abuts against a stationary contact, thereby improving the short-circuit resistance of the DC contactor and preventing the product from exploding or catching fire due to being repelled away by electric repulsion force during a short circuit. Moreover, since the elastic member begins to apply an elastic force toward the stationary contact to the moving contact piece after the push rod group moves a certain distance, that is, after the contact spring is further compressed, the elastic force curve superimposed by the elastic member and the contact spring on the moving contact piece will not touch or intersect with the suction force curve of the electromagnetic mechanism, thereby preventing the occurrence of a secondary attraction phenomenon and improving the working stability and service life of the DC contactor. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a curve diagram of the suction force of the electromagnetic mechanism of the utility model, the elastic force of the contact spring, and the superimposed elastic force of the contact spring and the elastic member;

[0025] Figure 2 It is a cross-sectional view of the first embodiment of the DC contactor of the utility model;

[0026] Figure 3 It is a stereoscopic diagram of the assembly of the push rod group and the moving contact piece of the first embodiment of the DC contactor of the utility model;

[0027] Figure 4 It is a cross-sectional view of the assembly of the push rod assembly and the moving contact piece of the first embodiment of the DC contactor of the utility model;

[0028] Figure 5 This is an exploded view of the push rod assembly and the moving contact piece of the first embodiment of the DC contactor of the utility model;

[0029] Figure 6 It is a cross-sectional view of the assembly of the push rod assembly and the moving contact piece of the second embodiment of the DC contactor of the utility model;

[0030] Combined with the accompanying drawings, the following description is given:

[0031] 1. Static contact; 2. Moving contact piece; 3. Push rod assembly; 31. Contact spring; 32. Elastic member; 33. Push rod; 331. Step portion; 34. Support sheet; 35. Bracket; 351. Main body; 3511. Avoidance hole; 352. Buckle portion; 36. Limiting member; 4. Magnetic shell; 5. Shielding shell; 6. Pole piece; 7. Moving iron core; 8. Pole core; 9. Coil winding. DETAILED DESCRIPTION

[0032] The preferred embodiments of the present invention are described in detail below in conjunction with the accompanying drawings.

[0033] Embodiment 1

[0034] See also Figure 2 The utility model provides a DC contactor, including: an outer shell, a static contact 1, a moving contact piece 2, a push rod group 3 and an electromagnetic mechanism. The outer shell can be, but is not limited to, composed of a magnetic shell 4 and a shielding shell 5. The magnetic shell 4 is in the shape of a round cup with a bottom and no top. The shielding shell 5 is fixedly covered in the upper port of the magnetic shell 4.

[0035] This article takes two stationary contacts 1 as an example for detailed description, but it does not mean that the present application is limited to the DC contactor with two stationary contacts 1. For example, in other embodiments, the DC contactor may include four stationary contacts 1. The two stationary contacts 1 are fixed side by side on the top of the shielding shell 5, and the lower ends of the two stationary contacts 1 extend vertically downward into the shielding shell 5, and the upper ends of the two stationary contacts 1 protrude vertically upward from the shielding shell 5 for connection to the load circuit.

[0036] Furthermore, the moving contact piece 2 is accommodated in the shielding shell 5, and the two ends of the moving contact piece 2 are spaced relative to the lower ends of the two stationary contacts 1. The push rod group 3 and the electromagnetic mechanism are both accommodated in the magnetic shell 4, and the electromagnetic mechanism is at the inner bottom of the magnetic shell 4, and the push rod group 3 is connected between the moving contact piece 2 and the electromagnetic mechanism.

[0037] The movable contact piece 2 is movably mounted on the upper end of the push rod group 3, and the movable contact piece 2 can move up and down on the push rod group 3. The push rod group 3 includes a contact spring 31. When the electromagnetic mechanism is powered off, the contact spring 31 is also in a certain compression state and always directly or indirectly applies an elastic force to the movable contact piece 2 in the direction of the stationary contact 1. The electromagnetic mechanism is used to drive the push rod group 3 to push the movable contact piece 2 to move upward and abut against the stationary contact 1.

[0038] The DC contactor has two states, namely, the release state when the electromagnetic mechanism is powered off and the pull-in state when the electromagnetic mechanism is powered on. In the process of switching the DC contactor from the release state to the pull-in state, the movement of the push rod group 3 and the moving contact piece 2 is divided into two stages. The first stage: the push rod group 3 and the moving contact piece 2 move synchronously until the moving contact piece 2 abuts against the two stationary contacts 1; the second stage: the moving contact piece 2 is blocked by the two stationary contacts 1 and no longer moves. The push rod group 3 is driven by the electromagnetic mechanism to continue to move upward for a short distance and then stops, so that the push rod group 3 will move over the distance relative to the moving contact piece 2, that is, the upward movement distance of the push rod group 3 is greater than the upward movement distance of the moving contact piece 2, and the contact spring 31 is further compressed. The elastic force applied by the contact spring 31 to the moving contact piece 2 makes the moving contact piece 2 stably and reliably abut against the two stationary contacts 1.

[0039] For ease of understanding, the further compressed amount of the contact spring 31 is defined as M millimeters, wherein the “further compressed amount” does not include the compressed amount of the contact spring 31 in the released state.

[0040] As one of the important improvements of the present application, the push rod group 3 also includes an elastic member 32, which is used to start applying an elastic force to the moving contact piece 2 in the direction of the static contact 1 after the contact spring 31 is further compressed to a compression amount of N millimeters; that is, in the process of the DC contactor switching from the released state to the attracted state, in the first stage, the elastic member 32 does not apply an elastic force to the moving contact piece 2, and in the second stage, when the push rod group 3 continues to move N millimeters (that is, the contact spring 31 is further compressed to a compression amount of N millimeters), the elastic member 32 does not apply an elastic force to the moving contact piece 2, and in the continued movement stroke after the push rod group 3, the elastic member 32 starts to apply an elastic force to the moving contact piece 2 in the direction of the static contact 1 until it reaches the end of the stroke, that is, the position where the contact spring 31 is further compressed to a compression amount of M millimeters, and the DC contactor is in the attracted state.

[0041] Wherein, 0<N<M, when the DC contactor is in the closed state, the compression amount of the elastic member 32 is MN millimeters.

[0042] The utility model adopts the method of using the elastic member 32 in conjunction with the contact spring 31 to provide pressure for the moving contact piece 2, so that the moving contact piece 2 can stably and reliably abut against the stationary contact 1, and the contact pressure of the DC contactor is greater, thereby improving the short-circuit resistance of the DC contactor, preventing the product from exploding or catching fire due to the electric repulsion force during a short circuit, and making the contact resistance between the moving contact piece 2 and the stationary contact 1 smaller; in addition, since the elastic member 32 starts to apply an elastic force to the moving contact piece 2 in the direction of the stationary contact 1 after the push rod group 3 moves a certain distance, that is, after the contact spring 31 is further compressed, the elastic force curve of the elastic member 32 and the contact spring 31 on the moving contact piece 2 is as shown in FIG. Figure 1 As shown in curve ③, it will not touch or intersect with the suction curve of the electromagnetic mechanism (curve ④), thereby preventing the secondary attraction phenomenon and improving the working stability and life of the DC contactor.

[0043] See also Figures 3 to 5 The push rod assembly 3 further includes a push rod 33 and a support sheet 34 disposed on the push rod 33. The support sheet 34 may be, but is not limited to, an annular gasket. A step portion 331 is disposed in the middle of the push rod 33. The support sheet 34 is sleeved on the push rod 33 and stopped at the top of the step portion 331. The elastic member 32 is arranged between the movable contact piece 2 and the support sheet 34.

[0044] It should be noted that the elastic member 32 in the present invention can be any one or a combination of a spring, a leaf spring, and an elastic washer. In this embodiment, the elastic member 32 is preferably a spring. Of course, in view of the non-enumerability of the elastic member 32, in addition to the optional solutions given, any elastic member 32 that can be replaced with a spring without creative labor should also be considered within the scope of protection of this application.

[0045] Furthermore, a bracket 35 is installed on the moving contact piece 2, and the elastic member 32 is fixed to the bottom of the moving contact piece 2 through the bracket 35, and in the natural state (i.e., the released state), the lower end of the elastic member 32 and the support piece 34 do not contact each other, and the distance between the two is N millimeters, thereby achieving that in the second stage when the push rod group 3 continues to move N millimeters, the lower end of the elastic member 32 will not contact the support piece 34, and thus will not apply an elastic force to the moving contact piece 2.

[0046] It is worth mentioning that in this embodiment, the bracket 35 is made of plastic material, and the upper end of the elastic member 32 is integrally injection molded in the bracket 35. The bracket 35 is provided with a main body 351 and two symmetrical buckle parts 352 extending upward from both sides of the main body 351. The main body 351 is attached to the bottom surface of the movable contact piece 2, and the two buckle parts 352 are respectively buckled on both sides of the movable contact piece 2, so as to realize the fixing of the elastic member 32 to the bottom of the movable contact piece 2 through the bracket 35. This fixing method has a simple structure and is easy to assemble.

[0047] See also Figure 4 The movable contact piece 2 can be slidably mounted on the upper end of the push rod 33, and the push rod 33 is located above the movable contact piece 2 and fixed with a limiter 36, which can be but not limited to a clip, and is clamped and fixed to the push rod 33. The middle part of the main body 351 of the bracket 35 is provided with an avoidance hole 3511 for the push rod 33 to pass through, the lower end of the contact spring 31 elastically abuts against the support piece 34, and the upper end of the contact spring 31 passes through the avoidance hole 3511 and elastically abuts against the bottom surface of the movable contact piece 2. In the natural state (i.e., the released state), the movable contact piece 2 is stopped upward at the bottom of the limiter 36 by the elastic force of the contact spring 31.

[0048] In this embodiment, the elastic member 32 is a spring, which is sleeved on the outer side of the contact spring 31 .

[0049] Optionally, M satisfies the formula: 1≤M≤3; N satisfies the formula: 0.5≤N≤2.5.

[0050] In this embodiment, M is preferably 2 mm and N is preferably 1.5 mm.

[0051] It should be noted that the electromagnetic mechanism adopts existing conventional technology, and its specific structure is not limited. Figure 2 As shown, the electromagnetic mechanism in this embodiment includes a pole piece 6, a moving iron core 7, a pole core 8 and a coil winding 9. The coil winding 9 is arranged at the inner bottom of the magnetic shell 4. The pole piece 6 is located between the shielding shell 5 and the coil winding 9. The lower end of the push rod 33 extends vertically downward after passing through the through hole in the middle of the pole piece 6. The moving iron core 7 is installed at the lower end of the push rod 33, and a reset spring is arranged between the moving iron core 7 and the pole piece 6; the pole core 8 is cylindrical, which is sleeved outside the moving iron core 7, and the coil winding 9 is sleeved outside the pole core 8.

[0052] When the coil winding 9 is energized, the magnetic field it generates forms a magnetic circuit between the magnetic shell 4, the pole piece 6, the moving iron core 7 and the pole core 8. The moving iron core 7 moves upward due to the magnetic attraction of the pole piece 6, and pushes the moving contact piece 2 to abut against the static contact 1 through the push rod group 3, completing the first stage of movement; thereafter, the moving iron core 7 continues to move upward until it is attracted to the bottom of the pole piece 6, and the moving iron core 7 pushes the push rod group 3 to continue to move upward, completing the second stage of movement; in the second stage, when the push rod group 3 continues to move N millimeters, the elastic member 32 does not contact the support piece 34 and does not apply an elastic force to the moving contact piece 2, but in the continued movement of the push rod group 3, the elastic member 32 begins to contact the support piece 34 and applies an elastic force to the moving contact piece 2 in the direction of the static contact 1 until it reaches a position where the contact spring 31 is further compressed by M millimeters, at which time the DC contactor is in the attracted state.

[0053] When the coil winding 9 is de-energized, the movable contact piece 2, the push rod assembly 3 and the movable iron core 7 are restored to their original positions under the elastic force of the contact spring 31, the elastic member 32 and the reset spring, so that the DC contactor is in a released state.

[0054] Embodiment 2

[0055] The elastic member 32 in this embodiment is also a spring, but the installation method of the elastic member 32 is different from that in the first embodiment.

[0056] For details, see Figure 6The elastic member 32 is sleeved on the outside of the contact spring 31, and the lower end of the elastic member 32 is fixed to the top of the support sheet 34 by welding or the like. In the natural state (i.e., the released state), the upper end of the elastic member 32 does not contact the moving contact sheet 2, and the distance between the two is N millimeters.

[0057] This embodiment adopts this structural design and can also achieve that after the push rod assembly 3 moves a certain distance, the contact spring 31 is further compressed N millimeters before it starts to apply an elastic force to the moving contact piece 2 in the direction of the stationary contact 1 .

[0058] In summary, the DC contactor of the utility model is provided with a contact spring 31 and an elastic member 32 on the push rod group 3. The elastic member 32 and the contact spring 31 jointly provide pressure for the moving contact piece 2, so that the moving contact piece 2 can stably and reliably abut against the static contact 1, thereby improving the short-circuit resistance of the DC contactor and preventing the product from exploding or catching fire due to the electric repulsion force during a short circuit. Moreover, since the elastic member 32 starts to apply an elastic force to the moving contact piece 2 toward the static contact 1 after the push rod group 3 moves a certain distance, that is, after the contact spring 31 is further compressed, the elastic force curve superimposed by the elastic member 32 and the contact spring 31 on the moving contact piece 2 will not touch or intersect with the suction curve of the electromagnetic mechanism, thereby preventing the secondary attraction phenomenon and improving the working stability and service life of the DC contactor.

[0059] In the above description, many specific details are described to facilitate a full understanding of the present invention. However, the above description is only a preferred embodiment of the present invention. The present invention can be implemented in many other ways different from those described herein, so the present invention is not limited by the specific implementation disclosed above. At the same time, any person familiar with the technical field can make many possible changes and modifications to the technical solution of the present invention by using the methods and technical contents disclosed above without departing from the scope of the technical solution of the present invention, or modify it into an equivalent embodiment of equivalent changes. Any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still falls within the scope of protection of the technical solution of the present invention.

Claims

1. A DC contactor, comprising: outer shell; A stationary contact (1), the stationary contact (1) being fixed to the outer shell; A moving contact piece (2), the moving contact piece (2) being accommodated in the outer shell and arranged opposite to the stationary contact (1); and a push rod group (3) and an electromagnetic mechanism both accommodated in the outer shell, the movable contact piece (2) being movably mounted on the push rod group (3) and being exerted with an elastic force in the direction of the stationary contact (1) by a contact spring (31) of the push rod group (3), the electromagnetic mechanism being used to drive the push rod group (3) to push the movable contact piece (2) to abut against the stationary contact (1), and the moving distance of the push rod group (3) being greater than the moving distance of the movable contact piece (2), so that the contact spring (31) is further compressed; wherein the further compression amount of the contact spring (31) is M millimeters; The feature is that the push rod assembly (3) comprises an elastic member (32), and the elastic member (32) is used to apply an elastic force on the moving contact piece (2) in the direction of the stationary contact (1) after the contact spring (31) is further compressed to a compression amount of N millimeters; wherein 0<N<M.

2. The DC contactor according to claim 1, characterized in that: The push rod assembly (3) further comprises a push rod (33) and a support sheet (34) arranged on the push rod (33); the elastic member (32) is arranged between the movable contact sheet (2) and the support sheet (34).

3. The DC contactor according to claim 2, characterized in that: The elastic member (32) is fixed to the bottom of the movable contact piece (2) via a bracket (35), and in a natural state, the lower end of the elastic member (32) and the support piece (34) do not contact each other, and the distance between the two is N millimeters.

4. The DC contactor according to claim 3, characterized in that: The bracket (35) is made of plastic material, and the upper end of the elastic member (32) is integrally injection-molded in the bracket (35).

5. The DC contactor according to claim 3, characterized in that: The bracket (35) is provided with a main body (351) and two symmetrical buckle parts (352) extending upward from both sides of the main body (351), the main body (351) is abutted against the bottom surface of the movable contact piece (2), and the two buckle parts (352) are respectively buckled on both sides of the movable contact piece (2).

6. The DC contactor according to claim 5, characterized in that: The movable contact piece (2) can be slidably mounted on the upper end of the push rod (33), and the push rod (33) is located above the movable contact piece (2) and fixed with a limiting member (36); a middle portion of the main body (351) is provided with an avoidance hole (3511) for the push rod (33) to pass through; the lower end of the contact spring (31) elastically abuts against the support piece (34); and the upper end of the contact spring (31) passes through the avoidance hole (3511) and elastically abuts against the bottom surface of the movable contact piece (2); In a natural state, the movable contact piece (2) is stopped upward at the bottom of the limiting member (36) by the elastic force of the contact spring (31).

7. The DC contactor according to claim 6, characterized in that: The elastic member (32) is a spring, which is sleeved on the outside of the contact spring (31).

8. The DC contactor according to claim 2, characterized in that: The lower end of the elastic member (32) is fixedly connected to the support sheet (34), and in a natural state, the upper end of the elastic member (32) and the movable contact sheet (2) are not in contact with each other, and the distance between the two is N millimeters.

9. The DC contactor according to claim 1, characterized in that: The elastic member (32) is any one of a spring, a leaf spring, and an elastic washer, or a combination thereof.

10. The DC contactor according to claim 1, characterized in that: The M satisfies the formula: 1≤M≤3; the N satisfies the formula: 0.5≤N≤2.5.

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