Bidirectional pump and material injection device

Abstract

The application provides a bidirectional pump and a material injection device. The bidirectional pump and the material injection device comprise a first cylinder body having a first inner cavity, a first bottom wall of the first cylinder body being provided with a first communication hole and a second communication hole; a first piston in sliding sealing cooperation with an inner wall of the first cylinder body; a switching device, the switching device being provided with a first central hole and a second central hole which are not communicated with each other in an axial direction, the switching device being provided with a first injection hole, a second injection hole and a front through hole which are communicated with the first central hole in a radial direction, and the switching device being provided with a rear through hole which is communicated with the second central hole in the radial direction; a first circulation pipe communicated with the first cavity; and a second circulation pipe communicated with the first cavity. The bidirectional pump and the material injection device can solve the problem of low color mixing efficiency caused by the fact that the existing reciprocating pump needs a one-way stroke to specially extract the color paste.

Description

Technical Field

[0001] This invention relates to the field of material pump technology, and more specifically, to a bidirectional pump and material dispensing device. Background Technology

[0002] Color mixing requires strict control over the amount of pigment. When dispensing large amounts of pigment (e.g., more than 15 ml), the error in the amount dispensed cannot exceed a certain percentage (e.g., less than 1%). Similarly, when dispensing small amounts of pigment (e.g., 0.077 ml), the error cannot exceed a certain percentage (e.g., less than ±24%). To ensure dispensing accuracy, a reciprocating pump is generally used. In the field of color mixing technology, using a reciprocating pump to dispense a fixed amount of pigment is a key technology. Common reciprocating volumetric pumps include piston pumps, plunger pumps, and pleated pumps. In the prior art known to the inventor, reciprocating pumps are unidirectional pumps, meaning that one unidirectional stroke in the reciprocating motion is dedicated to extracting pigment. Therefore, extracting pigment consumes part of the color mixing time, resulting in low color mixing efficiency. Summary of the Invention

[0003] The main objective of this invention is to provide a bidirectional pump and material dispensing device that can solve the problem of low color mixing efficiency caused by the need for a unidirectional stroke to extract color paste when using existing reciprocating pumps.

[0004] To achieve the above objectives, according to one aspect of the present invention, a bidirectional pump is provided, comprising: a first cylinder having a first inner cavity, the bottom wall of the first cylinder having a first connecting hole and a second connecting hole; a first piston located within the first inner cavity, the first piston slidingly sealingly engaging with the inner wall of the first cylinder, the first piston dividing the first inner cavity into a first cavity and a second cavity, the first connecting hole and the second connecting hole both communicating with the second cavity; a switching device having a first center hole and a second center hole that are not interconnected along the axial direction, a first injection hole, a second injection hole, and a front through hole communicating with the first center hole along the radial direction, and a rear through hole communicating with the second center hole along the radial direction, the switching device having a first switching state and a second switching state; a first circulation pipe communicating with the first cavity; and a second circulation pipe communicating with the first cavity. The two chambers are connected. In the first switching state of the switching device, the front through hole is connected to the first connecting hole, and the second circulation pipe is connected to the rear through hole. In this state of the switching device, the first piston slides along the first direction to compress the second chamber. The material enters the first chamber sequentially from the second central hole, the rear through hole, and the second circulation pipe. At the same time, the material in the second chamber is discharged sequentially from the second chamber, the first connecting hole, the front through hole, the first central hole, and the first injection hole. In the second switching state of the switching device, the front through hole is connected to the first circulation pipe, and the rear through hole is connected to the second connecting hole. In this state of the switching device, the first piston slides along the second direction to compress the first chamber. The material enters the second chamber sequentially from the second central hole, the rear through hole, and the second connecting hole. At the same time, the material in the first chamber is discharged sequentially from the first chamber, the first circulation pipe, the front through hole, the first central hole, and the second injection hole.

[0005] Furthermore, the bidirectional pump also includes a first housing, on which a discharge hole is provided. The first housing has an installation cavity communicating with the discharge hole. The first injection hole, the second injection hole, the front through hole, the rear through hole, the second cavity, the first connecting hole, the second connecting hole, the first circulation pipe, and the second circulation pipe are all communicating with the installation cavity. The switching device is in a sealed and movable fit with the inner wall of the installation cavity. In the first switching state of the switching device, the first injection hole is communicating with the discharge hole. In the second switching state of the switching device, the second injection hole is communicating with the discharge hole.

[0006] Furthermore, the switching device has a third injection hole that communicates with the first central hole in the radial direction. The diameter of the third injection hole is smaller than the diameter of the first injection hole and the diameter of the second injection hole. The switching device has a third switching state. In the third switching state of the switching device, the third injection hole communicates with the discharge hole.

[0007] Furthermore, the bidirectional pump also includes: a second cylinder having a second inner cavity; a second piston capable of slidingly sealing with the second cylinder, the second inner cavity communicating with the second cavity; and a piston rod slidably disposed relative to the first and second inner cavities, the first and second pistons being connected to the piston rod; the switching device has a central through hole communicating with the first central hole along the radial direction, and in the first switching state or the third switching state of the switching device, the second inner cavity communicating with the first central hole through the central through hole.

[0008] Furthermore, the bidirectional pump also includes a third circulation pipe, which is connected to the first chamber. In the first or third switching state of the switching device, the third circulation pipe is connected to the second central hole through the rear through hole.

[0009] Furthermore, multiple rear through holes are provided. In the first switching state of the switching device, the front through hole is connected to the first connecting hole, the middle through hole is connected to the second inner cavity, and the second circulation pipe and the third circulation pipe are connected to the rear through holes one by one. In the second switching state of the switching device, the front through hole is connected to the first circulation pipe, and the second connecting hole and the second inner cavity are connected to the same rear through hole. In the third switching state of the switching device, the middle through hole is connected to the second inner cavity, and the second connecting hole, the second circulation pipe and the third circulation pipe are connected to the rear through holes one by one. The second connecting hole and the second inner cavity are connected to the same rear through hole.

[0010] Furthermore, the bidirectional pump also includes a return pipe, which is connected to the mounting cavity. The switching device has a fourth switching state, a fifth switching state, and a sixth switching state. In the fourth switching state of the switching device, the first injection port is connected to the return pipe. In the fifth switching state of the switching device, the second injection port is connected to the return pipe. In the sixth switching state of the switching device, the third injection port is connected to the return pipe.

[0011] Furthermore, multiple rear through holes are provided. In the fourth switching state of the switching device, the front through hole is connected to the first connecting hole, the middle through hole is connected to the second inner cavity, and the second circulation pipe and the second circulation pipe are connected to the rear through holes one by one. In the fifth switching state of the switching device, the front through hole is connected to the first circulation pipe, and the second connecting hole and the second inner cavity are connected to the same rear through hole. In the sixth switching state of the switching device, the middle through hole is connected to the second inner cavity, and the second connecting hole, the second circulation pipe and the third circulation pipe are connected to the rear through holes one by one. The second connecting hole and the second inner cavity are connected to the same rear through hole.

[0012] Furthermore, the front through hole includes a first front through hole and a second front through hole, with the axis of the first front through hole and the axis of the second front through hole located on a first straight line; the middle through hole includes a first middle through hole, a second middle through hole, a third middle through hole, and a fourth middle through hole, with the axis of the first middle through hole and the axis of the second middle through hole located on a second straight line, and the axis of the third middle through hole and the axis of the fourth middle through hole located on a third straight line; the rear through hole includes a first rear through hole, a second rear through hole, a third rear through hole, and a fourth rear through hole, with the axis of the first rear through hole and the axis of the second rear through hole located on a fourth straight line, and the axis of the third rear through hole and the axis of the fourth rear through hole located on a fifth straight line.

[0013] Furthermore, the first straight line is parallel to the second straight line, the second straight line is at an angle of 60° to the third straight line, the third straight line is parallel to the fourth straight line, the fourth straight line is at an angle of 60° to the fifth straight line, the switching device rotates and seals with the mounting cavity, and the rotation angle of the switching device in the first switching state, the second switching state, the third switching state, the fourth switching state, the fifth switching state and the sixth switching state differs by 60° in sequence.

[0014] Furthermore, the axes of the first injection hole, the second injection hole, and the third injection hole are located in the first plane, the axis of the front through hole is located in the second plane, the axis of the middle through hole is located in the third plane, and the axis of the rear through hole is located in the fourth plane. The first, second, third, and fourth planes are parallel to each other and are arranged sequentially along the axis of the switching device.

[0015] Furthermore, the bidirectional pump also includes a second housing with a circulation channel, through which the first circulation pipe, the second circulation pipe, and the third circulation pipe are all connected to the first chamber.

[0016] Furthermore, the first housing has a first connecting channel, a second connecting channel and a third connecting channel. The first circulation pipe is connected to the mounting cavity through the first connecting channel, the second circulation pipe is connected to the mounting cavity through the second connecting channel, and the third circulation pipe is connected to the mounting cavity through the third connecting channel.

[0017] According to another aspect of the present invention, a material dispensing device is provided, comprising a material tank and the aforementioned bidirectional pump, wherein the second central hole of the bidirectional pump is in communication with the material tank.

[0018] Applying the technical solution of this invention, in the first switching state of the switching device, the first piston slides along the first direction, allowing material to enter the first chamber, while simultaneously, material in the second chamber is discharged from the first injection hole. In the second switching state of the switching device, the first piston slides along the second direction, allowing material to enter the second chamber, while simultaneously, material in the first chamber is discharged from the second injection hole. In one switching state, one stroke of the first piston can simultaneously realize the injection and discharge of material. The injected material prepares for the next discharge, eliminating the need for a separate stroke to extract material, thus saving time. When mixing color paste, the material is the color paste itself. The bidirectional pump of this invention saves the time of extracting color paste and improves color mixing efficiency. Attached Figure Description

[0019] The accompanying drawings, which form part of this specification, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0020] Figure 1 A schematic diagram of the structure of a bidirectional pump according to an embodiment of the present invention is shown;

[0021] Figure 2 It shows Figure 1 A schematic diagram of the bidirectional pump from another angle;

[0022] Figure 3 It shows Figure 1 A schematic diagram of the structure of the internal passage of the first housing and the first cylinder of the bidirectional pump;

[0023] Figure 4 It shows Figure 1 A schematic diagram of the switching device for a bidirectional pump;

[0024] Figure 5 It shows Figure 4 A cross-sectional view of the switching device;

[0025] Figure 6 It shows Figure 4 Side view of the switching device;

[0026] Figure 7 It shows Figure 6 Sectional view along direction II;

[0027] Figure 8 It shows Figure 6 A cross-sectional view along the JJ direction;

[0028] Figure 9 It shows Figure 6 A cross-sectional view along the KK direction;

[0029] Figure 10 It shows Figure 6 Cross-sectional view along the MM direction;

[0030] Figure 11 It shows Figure 6 A cross-sectional view along the LL direction;

[0031] Figure 12 A first cross-sectional view of a bidirectional pump according to an embodiment of the present invention is shown in the first switching state of the switching device;

[0032] Figure 13 A second cross-sectional view of a bidirectional pump according to an embodiment of the present invention is shown in the first switching state of the switching device;

[0033] Figure 14 A third cross-sectional view of a bidirectional pump according to an embodiment of the present invention is shown in which the switching device is in a first switching state;

[0034] Figure 15 A fourth cross-sectional view of a bidirectional pump according to an embodiment of the present invention is shown in which the switching device is in a first switching state;

[0035] Figure 16 A fifth cross-sectional view of a bidirectional pump according to an embodiment of the present invention is shown in the first switching state of the switching device;

[0036] Figure 17 A first cross-sectional view of a bidirectional pump according to an embodiment of the present invention is shown in the second switching state of the switching device;

[0037] Figure 18 A second cross-sectional view of a bidirectional pump according to an embodiment of the present invention is shown in the second switching state of the switching device;

[0038] Figure 19 A third cross-sectional view of a bidirectional pump according to an embodiment of the present invention is shown in which the switching device is in a second switching state;

[0039] Figure 20 A fourth cross-sectional view of a bidirectional pump according to an embodiment of the present invention is shown in which the switching device is in a second switching state;

[0040] Figure 21 A fifth cross-sectional view of a bidirectional pump according to an embodiment of the present invention is shown in which the switching device is in a second switching state;

[0041] Figure 22 A first cross-sectional view of a bidirectional pump according to an embodiment of the present invention is shown in the third switching state of the switching device;

[0042] Figure 23 A second cross-sectional view of a bidirectional pump according to an embodiment of the present invention is shown in the third switching state of the switching device;

[0043] Figure 24 A third cross-sectional view of a bidirectional pump according to an embodiment of the present invention is shown in the third switching state of the switching device;

[0044] Figure 25 A fourth cross-sectional view of a bidirectional pump according to an embodiment of the present invention is shown in the third switching state of the switching device;

[0045] Figure 26 A fifth cross-sectional view of a bidirectional pump according to an embodiment of the present invention is shown in the third switching state of the switching device;

[0046] Figure 27 A first cross-sectional view of a bidirectional pump according to an embodiment of the present invention is shown in the fourth switching state of the switching device;

[0047] Figure 28 A second cross-sectional view of a bidirectional pump according to an embodiment of the present invention is shown in the fourth switching state of the switching device;

[0048] Figure 29 A third cross-sectional view of a bidirectional pump according to an embodiment of the present invention is shown in the fourth switching state of the switching device;

[0049] Figure 30 A fourth cross-sectional view of a bidirectional pump according to an embodiment of the present invention is shown in the fourth switching state of the switching device;

[0050] Figure 31 A fifth cross-sectional view of a bidirectional pump according to an embodiment of the present invention is shown in the fourth switching state of the switching device;

[0051] Figure 32 A first cross-sectional view of a bidirectional pump according to an embodiment of the present invention is shown in the fifth switching state of the switching device;

[0052] Figure 33 A second cross-sectional view of a bidirectional pump according to an embodiment of the present invention is shown in the fifth switching state of the switching device;

[0053] Figure 34 A third cross-sectional view of a bidirectional pump according to an embodiment of the present invention is shown in the fifth switching state of the switching device;

[0054] Figure 35 A fourth cross-sectional view of a bidirectional pump according to an embodiment of the present invention is shown in the fifth switching state of the switching device;

[0055] Figure 36 A fifth cross-sectional view of a bidirectional pump according to an embodiment of the present invention is shown in the fifth switching state of the switching device;

[0056] Figure 37A first cross-sectional view of a bidirectional pump according to an embodiment of the present invention is shown in the sixth switching state of the switching device;

[0057] Figure 38 A second cross-sectional view of a bidirectional pump according to an embodiment of the present invention is shown in the sixth switching state of the switching device;

[0058] Figure 39 A third cross-sectional view of a bidirectional pump according to an embodiment of the present invention is shown in the sixth switching state of the switching device;

[0059] Figure 40 A fourth cross-sectional view of a bidirectional pump according to an embodiment of the present invention is shown in the sixth switching state of the switching device; and

[0060] Figure 41 A fifth cross-sectional view of a bidirectional pump according to an embodiment of the present invention is shown in the sixth switching state of the switching device.

[0061] The above figures include the following reference numerals:

[0062] 1. Piston rod; 2. First piston; 3. Discharge port; 6. Second piston; 8. Handle; 11. Second housing; 20. First housing; 20a. Return channel; 20b. First connecting hole; 20c. Second inner cavity; 20d. Second connecting hole; 20f. Second connecting channel; 20g. First connecting channel; 20h. Third connecting channel; 21. Rotating rod; 22. Switching device; 28. Return pipe; 31. First cylinder; 31d. Second cavity; 31u. First cavity; 32L. First circulation pipe; 32R. Second circulation pipe; 32K. Third circulation pipe; M0. First center hole; N0. Second center hole; N1. First injection hole; N2. Second injection hole; N3. Third injection hole; N4. Front through hole; N5. Middle through hole; N6. Rear through hole. Detailed Implementation

[0063] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0064] See also Figures 1 to 26As shown, the present invention provides a bidirectional pump, comprising: a first cylinder 31 having a first inner cavity, the bottom wall of the first cylinder 31 having a first connecting hole 20b and a second connecting hole 20d; a first piston 2 located in the first inner cavity, the first piston 2 slidingly sealingly engaging with the inner wall of the first cylinder 31, the first piston 2 dividing the first inner cavity into a first cavity 31u and a second cavity 31d, the first connecting hole 20b and the second connecting hole 20d both communicating with the second cavity 31d; a switching device 22 having a first center hole M0 and a second center hole N0 that are not interconnected along the axial direction, a first injection hole N1, a second injection hole N2 and a front through hole N4 communicating with the first center hole M0 along the radial direction, and a rear through hole N6 communicating with the second center hole N0 along the radial direction, the switching device 22 having a first switching state and a second switching state; a first circulation pipe 32L communicating with the first cavity 31u; and a second circulation pipe 32R communicating with the first cavity 31u; in the first switching state of the switching device 22... In this state, the front through hole N4 is connected to the first connecting hole 20b, and the second circulation pipe 32R is connected to the rear through hole N6. In this state of the switching device 22, the first piston 2 slides along the first direction, compressing the second chamber 31d. Material sequentially enters the first chamber 31u from the second central hole N0, the rear through hole N6, and the second circulation pipe 32R. Simultaneously, material in the second chamber 31d is sequentially discharged from the second chamber 31d, the first connecting hole 20b, the front through hole N4, the first central hole M0, and the first discharge hole N1. In the switching device 2... In the second switching state of 2, the front through hole N4 is connected to the first circulation pipe 32L, and the rear through hole N6 is connected to the second connecting hole 20d. In this state of the switching device 22, the first piston 2 slides along the second direction to compress the first chamber 31u. The material enters the second chamber 31d sequentially from the second central hole N0, the rear through hole N6, and the second connecting hole 20d. At the same time, the material in the first chamber 31u is discharged sequentially from the first chamber 31u, the first circulation pipe 32L, the front through hole N4, the first central hole M0, and the second injection hole N2.

[0065] In this embodiment, the second central hole N0 is connected to the material bucket, which contains material. Both the first discharge hole N1 and the second discharge hole N2 can discharge material, and both the first cavity 31u and the second cavity 31d can store or discharge material. In the first switching state of the switching device 22, the first piston 2 is slid along the first direction, i.e., slid downwards, and the material in the material bucket enters the first cavity 31u. Simultaneously, the first discharge hole N1 discharges material from the second cavity 31d. In the second switching state of the switching device 22, the second piston 6 is slid along the second direction, i.e., slid upwards, and the material in the material bucket enters the second cavity 31d. Simultaneously, the second discharge hole N2 discharges material from the first cavity 31u. In one switching state of the switching device 22, within one unidirectional stroke, material injection and discharge can be achieved simultaneously. That is, material injection in the first chamber 31u and material discharge in the second chamber 31d are achieved simultaneously, and material injection in the second chamber 31d and material discharge in the first chamber 31u are achieved simultaneously. The injected material prepares the switching device 22 for material discharge in the next switching state. Through the design of the switching device 22, the first circulation pipe 32L and the second circulation pipe 32R, the first chamber 31u and the second chamber 31d can work simultaneously, with one discharging material and the other injecting material. There is no need to set up a special unidirectional stroke for material extraction, saving material extraction time and improving material discharge efficiency.

[0066] Specifically, the first cylinder 31 is a cylinder with a diameter of 40mm, a height of 150mm, and a single injection volume of 180ml. The material is a color paste. In the first switching state of the switching device 22, the first piston 2 is slid along the first direction, and the color paste is injected from the first injection hole N1. All the color paste in the second chamber 31d can be injected from the first injection hole N1. Under normal circumstances, the amount of color paste in the second chamber 31d is sufficient to meet the injection requirements. In the second switching state of the switching device 22, the first piston 2 is slid along the second direction, and the color paste is injected from the second injection hole N2. All the color paste in the first chamber 31u can be injected from the second injection hole N2, and the first chamber 31u is replenished with color paste from the color paste tank. Under normal circumstances, the amount of color paste in the first chamber 31u is sufficient to meet the injection requirements. If the amount of injected color paste is insufficient, the switching device 22 is switched back to the first switching state, and the first piston 2 is slid along the first direction again, and the color paste is injected from the first injection hole N1 again. The switching device 22 switches between the first switching state and the second switching state, and slides the first piston 2, until the amount of injected color paste meets the requirements.

[0067] See also Figures 1 to 26As shown, in one embodiment of the present invention, the bidirectional pump includes a first housing 20, on which a discharge hole 3 is provided. The first housing 20 has an installation cavity communicating with the discharge hole 3. A first injection hole N1, a second injection hole N2, a front through hole N4, a rear through hole N6, a second cavity 31d, a first connecting hole 20b, a second connecting hole 20d, a first circulation pipe 32L, and a second circulation pipe 32R are all communicating with the installation cavity. A switching device 22 is in a sealed and movable fit with the inner wall of the installation cavity. In the first switching state of the switching device 22, the first injection hole N1 is communicating with the discharge hole 3. In the second switching state of the switching device 22, the second injection hole N2 is communicating with the discharge hole 3.

[0068] In this embodiment, when the first injection hole N1 is connected to the discharge hole 3, the inner wall of the mounting cavity without the discharge hole 3 is used to block the second injection hole N2, preventing material from being discharged from the second injection hole N2; when the second injection hole N2 is connected to the discharge hole 3, the inner wall of the mounting cavity without the discharge hole 3 is used to block the first injection hole N1, preventing material from being discharged from the first injection hole N1. The switching device 22 moves relative to the mounting cavity, causing the first injection hole N1, the second injection hole N2 and the discharge hole 3 to connect, causing the front through hole N4 to connect with the first connecting hole 20b or the first circulation pipe 32L, and causing the rear through hole N6 to connect with both the second connecting hole 20d and the second inner cavity 20c, or to connect with the second circulation pipe 32R. The outer wall of the switching device 22 and the inner wall of the mounting cavity are always sealed to prevent materials in the second cavity 31d, the first connecting hole 20b, the second connecting hole 20d, the first circulation pipe 32L and the second circulation pipe 32R from entering the mounting cavity, thus avoiding leakage of materials from the gap between the outer wall of the switching device 22 and the inner wall of the mounting cavity.

[0069] Specifically, the switching device 22 is cylindrical, and the mounting cavity is adapted to the switching device 22. The switching device 22 is sealed and rotated with the inner wall of the mounting cavity. The switching device 22 switches to different switching states by rotating circumferentially relative to the mounting cavity. The rotation operation is simple and efficient.

[0070] See also Figures 1 to 26 As shown, in one embodiment of the present invention, the switching device 22 is provided with a third injection hole N3 that communicates with the first central hole M0 in the radial direction. The diameter of the third injection hole N3 is smaller than the diameter of the first injection hole N1 and the diameter of the second injection hole N2. The switching device 22 has a third switching state. In the third switching state of the switching device 22, the third injection hole N3 communicates with the discharge hole 3.

[0071] In this embodiment, the third injection hole N3 is used to inject a small amount of material. When the switching device 22 rotates to the third switching state, the third injection hole N3 is connected to the discharge hole 3, and the material is injected from the third injection hole N3. The small diameter of the third injection hole N3 allows for the injection of a small amount of material. Furthermore, the third injection hole N3 also facilitates control over the injection accuracy. When a small amount of material needs to be added after the first injection hole N1 and / or the second injection hole N2 has injected some material, continuing to use the first injection hole N1 or the second injection hole N2 could easily result in the amount of material added being greater than the required amount due to the large diameter of the first and second injection holes N1 and N2, making it impossible to control the injection accuracy. However, by using the third injection hole N3 to inject the material, the small diameter of the third injection hole N3 can control the injection amount, ensuring that the amount of material added is the same as or within an acceptable range as the required amount, thereby guaranteeing the injection accuracy.

[0072] Specifically, the diameter of the first injection hole N1 is 1.5 mm, the diameter of the second injection hole N2 is 4 mm, and the diameter of the third injection hole is 4 mm.

[0073] See also Figures 1 to 26 As shown, in one embodiment of the present invention, the bidirectional pump further includes: a second cylinder having a second inner cavity 20c; a second piston 6 capable of sliding and sealingly engaging with the second cylinder, the second inner cavity 20c communicating with the second cavity 31d; and a piston rod 1 slidably disposed relative to the first inner cavity and the second inner cavity 20c, the first piston 2 and the second piston 6 both being connected to the piston rod 1; the switching device 22 has a central through hole N5 radially connected to the first central hole M0, and in the first switching state or the third switching state of the switching device 22, the second inner cavity 20c is connected to the first central hole M0 through the central through hole N5.

[0074] In this embodiment, the second piston 6 slides along the second direction, entering the second inner cavity 20c. At this time, the second piston 6 and the second cylinder body are in sliding sealing cooperation. When a small amount of material needs to be injected or a small amount of material needs to be supplemented, the switching device 22 switches to the first switching state or the third switching state, so that the second inner cavity 20c is connected to the central through hole N5. The second piston 6 slides along the first direction, entering the second inner cavity 20c. The material in the second inner cavity 20c is discharged sequentially from the second inner cavity 20c, the central through hole N5, the first central hole M0, and the first injection hole N1, or sequentially from the second inner cavity 20c, the central through hole N5, the first central hole M0, and the third injection hole N3. The inner diameter of the second inner cavity 20c is smaller than the inner diameter of the first inner cavity, and the size of the second piston 6 is smaller than the size of the first piston 2, so that there is less material in the second inner cavity 20c. With the cooperation of the second piston 6, the amount of material injected from the second inner cavity 20c is small, which facilitates the control of the material injection accuracy.

[0075] Specifically, the second cylinder is a cylinder with a diameter of 14mm and a height of 30mm for the second inner cavity 20c. The second cylinder is coaxially arranged with the first cylinder 31.

[0076] See also Figures 1 to 26 As shown, in one embodiment of the present invention, the bidirectional pump further includes a third circulation pipe 32K, which is connected to the first cavity 31u. In the first switching state or the third switching state of the switching device 22, the third circulation pipe 32K is connected to the second central hole N0 through the rear through hole N6.

[0077] In this embodiment, in the first or third switching state of the switching device 22, the first piston 2 slides along the first direction to compress the second chamber 31d and / or the second inner chamber 20c, discharging the material in the second chamber 31d and / or the second inner chamber 20c. Simultaneously, the material in the material tank enters the first chamber 31u along the second circulation pipe 32R and the third circulation pipe 32K. The third circulation pipe 32K is designed to allow a large amount of material to enter the first chamber 31u simultaneously, quickly filling the first chamber 31u. The material in the first chamber 31u is used to discharge in the second switching state of the switching device 22. When a large amount of material needs to be injected at once, the switching device 22 switches to the second switching state, and the second injection hole N2 is used to discharge a large amount of material. In order to replenish the large amount of material in a timely manner, the second circulation pipe 32R and the third circulation pipe 32K are designed so that both can replenish the material in the first chamber 31u at the same time, improving the material injection efficiency.

[0078] See also Figures 1 to 26 As shown, in one embodiment of the present invention, multiple rear through holes N6 are provided. In the first switching state of the switching device 22, the front through hole N4 is connected to the first connecting hole 20b, the middle through hole N5 is connected to the second inner cavity 20c, and the second circulation pipe 32R and the third circulation pipe 32K are connected to the rear through holes N6 in a one-to-one correspondence. In the second switching state of the switching device 22, the front through hole N4 is connected to the first circulation pipe 32L, and the second connecting hole 20d and the second inner cavity 20c are connected to the same rear through hole N6. In the third switching state of the switching device 22, the middle through hole N5 is connected to the second inner cavity 20c, and the second connecting hole 20d, the second circulation pipe 32R, and the third circulation pipe 32K are connected to the rear through holes N6 in a one-to-one correspondence. The second connecting hole 20d and the second inner cavity 20c are connected to the same rear through hole N6.

[0079] In this embodiment, under different switching states of the switching device 22, different through holes are connected to different cavities or pipes to form different material flow channels, thereby resulting in different amounts of material flowing out. By switching the device 22 under different switching states, different amounts of material can be dispensed, which is highly practical and has a wide range of applications.

[0080] Specifically, the front through hole N4 includes a first front through hole and a second front through hole, the middle through hole N5 includes a first middle through hole, a second middle through hole, a third middle through hole and a fourth middle through hole, and the rear through hole N6 includes a first rear through hole, a second rear through hole, a third rear through hole and a fourth rear through hole. All four rear through holes N6 are elongated holes, which can simultaneously connect two flow channels to realize the convergence of materials in the two flow channels.

[0081] In the first switching state of the switching device 22, the first front through hole is connected to the first connecting hole 20b, the first middle through hole is connected to the second inner cavity 20c, the first rear through hole is connected to the third circulation pipe 32K, and the second rear through hole is connected to the second circulation pipe 32R. At this time, when the piston rod 1 is slid along the first direction, a portion of the material in the material bucket enters the first cavity 31u sequentially from the material bucket, the second central hole N0, the first rear through hole, and the third circulation pipe 32K. At the same time, another portion of the material in the material bucket enters the first cavity 31u sequentially from the material bucket, the second central hole N0, the second rear through hole, and the third circulation pipe 32K. The second circulation pipe 32R enters the first cavity 31u. At the same time, the material in the second cavity 31d is discharged sequentially from the second cavity 31d, the first connecting hole 20b, the first central hole M0 and the first injection hole N1. Meanwhile, the material in the second inner cavity 20c is discharged sequentially from the second inner cavity 20c, the first central through hole, the first central hole M0 and the first injection hole N1. That is, the material discharged from the first injection hole N1 is the material in the second cavity 31d and the second inner cavity 20c, which is a medium amount of material. When it is necessary to inject a medium amount of material, the switching device 22 is switched to the first switching state.

[0082] In the second switching state of the switching device 22, the first front through hole is connected to the first circulation pipe 32L, and the third rear through hole is simultaneously connected to the second connecting hole 20d and the second inner cavity 20c. At this time, when the piston rod 1 is slid along the second direction, a portion of the material in the material bucket sequentially enters the second cavity 31d from the material bucket, the second central hole N0, the third rear through hole, and the second connecting hole 20d. At the same time, another portion of the material in the material bucket sequentially enters the second inner cavity 20c from the material bucket, the second central hole N0, and the third rear through hole. Meanwhile, the material in the first cavity 31u sequentially flows from the first cavity 31u and the first circulation pipe 32L. 2L, the first front through hole, the first central hole M0, and the second injection hole N2 discharge. That is, the material discharged from the second injection hole N2 is the material in the first cavity 31u, which is a large amount of material. When a large amount of material needs to be injected, the switching device 22 is switched to the second switching state. If the amount of material injected by the switching device 22 in the second switching state still does not meet the injection quantity requirement, the switching device 22 is switched to the first switching state, and the piston rod 1 is slid along the first direction to increase the injection quantity of material. The switching device 22 switches back and forth between the first switching state and the second switching state until the amount of material meets the requirement.

[0083] In the third switching state of the switching device 22, the fourth through hole is connected to the second inner cavity 20c, the second rear through hole is simultaneously connected to the second connecting hole 20d and the second inner cavity 20c, the third rear through hole is connected to the third circulation pipe 32K, and the fourth rear through hole is connected to the second circulation pipe 32R. At this time, when the piston rod 1 is slid along the first direction, a portion of the material in the material bucket sequentially enters the first cavity 31u from the material bucket, the second central hole N0, the third rear through hole, and the third circulation pipe 32K. At the same time, another portion of the material in the material bucket sequentially enters the first cavity 31u from the material bucket, the first central hole M0, the fourth rear through hole, and the second circulation pipe 32R. Simultaneously, the material in the second cavity 31d flows back into the material tank sequentially through the second cavity 31d, the second connecting hole 20d, the second rear through hole, and the second central hole N0. Some or all of this material may not flow back into the material tank, but instead enter the first cavity 31u along with the material discharged from the material tank. Meanwhile, the material in the second inner cavity 20c is discharged sequentially through the second inner cavity 20c, the fourth central through hole, the first central hole M0, and the third injection hole N3. That is, the material discharged through the third injection hole N3 is the same material as that in the second inner cavity 20c, and is a small amount. When a small amount of material needs to be injected, the switching device 22 is switched to the third switching state. (See also...) Figures 1 to 11 , Figures 27 to 41 As shown, in one embodiment of the present invention, the bidirectional pump includes a return pipe 28, which is connected to the mounting cavity. The first injection port N1, the second injection port N2, or the third injection port N3 are connected to the return pipe 28 in at least one switching state of the switching device 22.

[0084] In this embodiment, the bidirectional pump further includes a return channel 20a. A return pipe 28 is connected to the mounting cavity via the return channel 20a and to the material tank. The return pipe 28 is used to form a circulation loop between the bidirectional pump and the material tank, allowing the material to flow within this loop and preventing blockage or dry blockage. This ensures that subsequent material can be smoothly discharged from the first discharge port N1, the second discharge port N2, and the third discharge port N3. The return pipe 28 is coaxial with the discharge port 3.

[0085] Specifically, the material is a color paste. After the bidirectional pump has been used for a period of time, the material inside the bidirectional pump is prone to dry blockage, especially the first injection hole N1, the second injection hole N2 and the third injection hole N3. At this time, it is necessary to clean the dry blockage channel. In order to reduce the difficulty of cleaning, a return pipe 28 is set up. The circulation loop formed by the return pipe 28 is used to unclog the dry blockage channel, thereby improving the convenience of dry blockage unclog.

[0086] See also Figures 1 to 11 , Figures 27 to 41As shown, in one embodiment of the present invention, the switching device 22 has a fourth switching state, a fifth switching state, and a sixth switching state. In the fourth switching state, the first injection hole N1 is connected to the return pipe 28. In the fifth switching state, the second injection hole N2 is connected to the return pipe 28. In the sixth switching state, the third injection hole N3 is connected to the return pipe 28.

[0087] In this embodiment, when the first injection hole N1 is blocked or dry-blocked, the switching device 22 is switched to the fourth switching state, and the piston rod 1 is slid along the first direction. The material flows back from the material tank, the first injection hole N1, and the return pipe 28 into the material tank in sequence, allowing the first injection hole N1 to flow. When the second injection hole N2 is blocked or dry-blocked, the switching device 22 is switched to the fifth switching state, and the piston rod 1 is slid along the second direction. The material flows back from the material tank, the second injection hole N2, and the return pipe 28 into the material tank in sequence, allowing the second injection hole N2 to flow. When the third injection hole N3 is blocked or dry-blocked, the switching device 22 is switched to the sixth switching state, and the piston rod 1 is slid along the first direction. The material flows back from the material tank, the third injection hole N3, and the return pipe 28 into the material tank in sequence, allowing the third injection hole N3 to flow. The pressure generated by the first piston 2 pushing the material clears the blocked or dry-blocked channels, making the operation convenient.

[0088] See also Figures 1 to 11 , Figures 27 to 41 As shown, in one embodiment of the present invention, multiple rear through holes N6 are provided. In the fourth switching state of the switching device 22, the front through hole N4 is connected to the first connecting hole 20b, the middle through hole N5 is connected to the second inner cavity 20c, and the second circulation pipe 32R and the second circulation pipe 32R are connected to the rear through holes N6 in a one-to-one correspondence. In the fifth switching state of the switching device 22, the front through hole N4 is connected to the first circulation pipe 32L, and the second connecting hole 20d and the second inner cavity 20c are connected to the same rear through hole N6. In the sixth switching state of the switching device 22, the middle through hole N5 is connected to the second inner cavity 20c, and the second connecting hole 20d, the second circulation pipe 32R and the third circulation pipe 32K are connected to the rear through holes N6 in a one-to-one correspondence. The second connecting hole 20d and the second inner cavity 20c are connected to the same rear through hole N6.

[0089] In this embodiment, under different switching states of the switching device 22, different through holes are connected to different cavities or pipes to form different material circulation loops, so that the material can flow through each hole, cavity and pipe, thereby ensuring that there is no blockage or dry blockage in all passages in the bidirectional pump. Through the cooperation of the switching device 22 and the return pipe 28, the anti-blocking function is achieved, which is highly practical.

[0090] Specifically, the front through hole N4 includes a first front through hole and a second front through hole, the middle through hole N5 includes a first middle through hole, a second middle through hole, a third middle through hole and a fourth middle through hole, and the rear through hole N6 includes a first rear through hole, a second rear through hole, a third rear through hole and a fourth rear through hole. All four rear through holes N6 are elongated holes, which can connect two paths at the same time and realize the convergence of materials in the two paths.

[0091] In the fourth switching state of the switching device 22, the second front through hole is connected to the first connecting hole 20b, the second middle through hole is connected to the second inner cavity 20c, the first rear through hole is connected to the second circulation pipe 32R, and the second rear through hole is connected to the third circulation pipe 32K. At this time, the piston rod 1 is slid along the first direction, and a part of the material in the material bucket enters the first cavity 31u sequentially from the material bucket, the second central hole N0, the first rear through hole, and the second circulation pipe 32R. At the same time, another part of the material in the material bucket enters the first cavity 31u sequentially from the material bucket, the second middle through hole N0, the second central through hole N0, the second rear through hole, and the second circulation pipe 32R. The material enters the first cavity 31u through the central hole N0, the second rear through hole, and the third circulation pipe 32K. Simultaneously, the material in the second cavity 31d flows back into the material container sequentially through the second cavity 31d, the first connecting hole 20b, the second front through hole, the first central hole M0, the first injection hole N1, the return channel 20a, and the return pipe 28. At the same time, the material in the second inner cavity 20c flows back into the material container sequentially through the second inner cavity 20c, the second central through hole, the first central hole M0, the first injection hole N1, the return channel 20a, and the return pipe 28. The fourth switching state of the switching device 22 can prevent the first injection hole N1 from clogging and also fill the material in the first cavity 31u.

[0092] In the fifth switching state of the switching device 22, the second front through hole is connected to the first circulation pipe 32L, and the fourth rear through hole is simultaneously connected to the second connecting hole 20d and the second inner cavity 20c. At this time, the piston rod 1 is slid along the second direction, and a portion of the material in the material bucket sequentially enters the second cavity 31d from the material bucket, the second central hole N0, the fourth rear through hole, and the second connecting hole 20d. At the same time, another portion of the material in the material bucket sequentially enters the second inner cavity 20c from the material bucket, the second central hole N0, and the fourth rear through hole. Meanwhile, the material in the first cavity 31u sequentially flows back to the material bucket from the first cavity 31u, the first circulation pipe 32L, the second front through hole, the first central hole M0, the second injection hole N2, the return channel 20a, and the return pipe 28. The fifth switching state of the switching device 22 can prevent the second injection hole N2 from being blocked and can also fill the material in the second cavity 31d and the second inner cavity 20c.

[0093] In the sixth switching state of the switching device 22, the third through hole is connected to the second inner cavity 20c, the first rear through hole is connected to the second connecting hole 20d and the second inner cavity 20c, the third rear through hole is connected to the second circulation pipe 32R, and the fourth rear through hole is connected to the third circulation pipe 32K. At this time, the piston rod 1 is slid along the first direction, and a part of the material in the material bucket enters the first cavity 31u from the material bucket, the second central hole N0, the third rear through hole and the second circulation pipe 32R in sequence. At the same time, another part of the material in the material bucket enters the first cavity 31u from the material bucket, the second central hole N0, the fourth rear through hole and the third circulation pipe 32K in sequence. At the same time, the material in the second cavity 31d flows back to the material bucket from the second cavity 31d, the second connecting hole 20d and the first rear through hole in sequence. At the same time, the material in the second inner cavity 20c flows back to the material bucket from the second inner cavity 20c, the third through hole, the first central hole M0, the first injection hole N1, the return channel 20a and the return pipe 28 in sequence. The sixth switching state of the switching device 22 can prevent the third injection hole N3 from being blocked, and can also fill the material in the first cavity 31u.

[0094] In actual use, the switching device 22 is first switched to the fourth, fifth and sixth switching states respectively to clear the channels in the bidirectional pump. At the same time, the materials in the first chamber 31u, the second chamber 31d and the second inner chamber 20c are filled. Then the switching device 22 is switched to the first, second or third switching states to discharge the materials, ensuring that the first chamber 31u, the second chamber 31d and the second inner chamber 20c are always filled with materials during the use of the bidirectional pump.

[0095] See also Figures 1 to 11 , Figures 27 to 41 As shown, in one embodiment of the present invention, the front through hole N4 includes a first front through hole and a second front through hole, the axis of the first front through hole and the axis of the second front through hole are located on a first straight line; the middle through hole N5 includes a first middle through hole, a second middle through hole, a third middle through hole and a fourth middle through hole, the axis of the first middle through hole and the axis of the second middle through hole are located on a second straight line, and the axis of the third middle through hole and the axis of the fourth middle through hole are located on a third straight line; the rear through hole N6 includes a first rear through hole, a second rear through hole, a third rear through hole and a fourth rear through hole, the axis of the first rear through hole and the axis of the second rear through hole are located on a fourth straight line, and the axis of the third rear through hole and the axis of the fourth rear through hole are located on a fifth straight line.

[0096] In this embodiment, the connection node between the first and second front through holes is located on the axis of the first central hole M0. The number and positional relationship of the front through holes N4 are set to adapt to the relative angles of the first injection hole N1, the second injection hole N2, and the third injection hole N3, as well as the relative position of the discharge hole 3 and the return pipe 28. This allows the switching device 22 to rotate 180° in the same direction, enabling a desired front through hole N4 to connect with the corresponding first connecting hole 20b or the first circulation pipe 32L. The intersection of the second and third straight lines is located on the axis of the first central hole M0. The number and positional relationship of the central through holes N5 are set to adapt to the relative angles of the first injection hole N1, the second injection hole N2, and the third injection hole N3, as well as the relative position of the discharge hole 3 and the return pipe 28. This allows the switching device 22 to rotate 60° or 120° in the same direction, enabling a desired central through hole N5 to connect with the second inner cavity 20c. The intersection of the fourth and fifth straight lines is located on the axis of the second central hole N0. The number and positional relationship of the rear through holes N6 are designed to accommodate the relative angles of the first injection hole N1, the second injection hole N2, and the third injection hole N3, as well as the relative positions of the discharge hole 3 and the return pipe 28. This allows the switching device 22 to rotate in the same direction by 60° or 120°, enabling a desired rear through hole N6 to connect with the corresponding second connecting hole 20d, the second inner cavity 20c, the second circulation pipe 32R, or the third circulation pipe 32K. The design of the front through hole N4, the middle through hole N5, and the rear through hole N6 ensures that each hole in the entire switching device 22 strictly corresponds to each switching state, thus forming the corresponding flow channels.

[0097] See also Figures 1 to 41 As shown, in one embodiment of the present invention, the first straight line is parallel to the second straight line, the second straight line is at an angle of 60° to the third straight line, the third straight line is parallel to the fourth straight line, the fourth straight line is at an angle of 60° to the fifth straight line, the switching device 22 is in rotational sealing fit with the mounting cavity, and the rotation angle of the switching device 22 in the first switching state, the second switching state, the third switching state, the fourth switching state, the fifth switching state and the sixth switching state differs by 60° in sequence.

[0098] In this embodiment, with Figure 12Using the orientation as a reference, the switching device 22 needs to rotate counterclockwise by 60° to switch from the first switching state to the second switching state, from the second switching state to the third switching state, from the third switching state to the fourth switching state, from the fourth switching state to the fifth switching state, and from the fifth switching state to the sixth switching state. For example, if the first switching state is recorded as 0°, the switching device 22 rotates counterclockwise by 60° to the second switching state, 120° to the third switching state, 180° to the fourth switching state, 240° to the fifth switching state, and 300° to the sixth switching state. The six switching states correspond to a full 360° circumference of the switching device 22, with the angle evenly distributed across the circumference. This facilitates the calculation of the angle of each rotation of the switching device 22 and prevents errors in the amount of material dispensed.

[0099] Specifically, the first end of the switching device 22 protrudes from the mounting cavity, the first central hole M0 is opened at the first end of the switching device 22, and the second central hole N0 is opened at the second end of the switching device 22. The bidirectional pump also includes a rotating rod 21, which is connected to the first end of the switching device 22. The axis of the rotating rod 21 is perpendicular to the axis of the switching device 22 in different planes. The switching device 22 can be manually rotated by the rotating rod 21, which is convenient for the operator to apply force.

[0100] In another embodiment, the outer wall of the first end of the switching device 22 is provided with an indicator arrow, and the second housing 11 is provided with an angle scale value along the outer periphery of the mounting cavity. The operator can know the switching state of the switching device 22 at this time according to the angle scale pointed to by the indicator arrow, and know the angle value of each rotation of the switching device 22.

[0101] See also Figures 1 to 41 As shown, in one embodiment of the present invention, the axis of the first injection hole N1, the axis of the second injection hole N2, and the axis of the third injection hole N3 are located in a first plane, the axis of the front through hole N4 is located in a second plane, the axis of the middle through hole N5 is located in a third plane, and the axis of the rear through hole N6 is located in a fourth plane. The first plane, the second plane, the third plane, and the fourth plane are parallel to each other and are arranged sequentially along the axial direction of the switching device 22.

[0102] In this embodiment, the axes of the three injection holes are in the same plane, so that the three injection holes do not occupy the axial area of ​​the switching device 22; the axes of the two front through holes N4 are in the same plane, so that the two front through holes N4 do not occupy the axial area of ​​the switching device 22; the axes of the four middle through holes N5 are in the same plane, so that the four middle through holes N5 do not occupy the axial area of ​​the switching device 22; and the axes of the four rear through holes N6 are in the same plane, so that the four rear through holes N6 do not occupy the axial area of ​​the switching device 22. Through the above arrangement, the switching device 22 is smaller in size and the opening positions are more compact.

[0103] See also Figures 1 to 41 As shown, in one embodiment of the present invention, the bidirectional pump includes a second housing 11, the second housing 11 having a circulation channel, and the first circulation pipe 32L, the second circulation pipe 32R and the third circulation pipe 32K are all connected to the first cavity 31u through the circulation channel.

[0104] In this embodiment, the first end of the three circulation pipes and the first cylinder 31 are all connected to the second housing 11 and communicate with the circulation channel. The first cylinder 31 is located between the second housing 11 and the first housing 20, making the overall structure of the bidirectional pump compact and visually symmetrical.

[0105] Specifically, the bidirectional pump also includes a handle 8, a piston rod 1 that passes through the second housing 11 and is slidably and sealingly connected to the second housing 11, a first end of the piston rod 1 located in the first inner cavity, and a second end of the piston rod 1 connected to the handle 8, the handle 8 located outside the second housing 11, and the piston rod 1 is manually slid by the handle 8.

[0106] In another embodiment, the piston rod 1 is driven to slide by a drive mechanism, which is a stepper motor or a servo motor.

[0107] See also Figures 1 to 41 As shown, in one embodiment of the present invention, the first housing 20 has a first communication channel 20g, a second communication channel 20f and a third communication channel 20h. The first circulation pipe 32L is connected to the mounting cavity through the first communication channel 20g, the second circulation pipe 32R is connected to the mounting cavity through the second communication channel 20f, and the third circulation pipe 32K is connected to the mounting cavity through the third communication channel 20h.

[0108] In this embodiment, the three circulation tubes correspond one-to-one with the three connecting channels, so that the three circulation tubes do not interfere with each other and have their own flow channels. Furthermore, the second end of each of the three circulation tubes is connected to the second housing 11. The three circulation tubes are supported by the first housing 20 and the second housing 11, resulting in strong stability.

[0109] Specifically, the first circulation pipe 32L, the second circulation pipe 32R, and the third circulation pipe 32K are all parallel to the first cylinder block 31.

[0110] The present invention also provides a material dispensing device, including a material tank and the aforementioned bidirectional pump, wherein the second central hole N0 of the bidirectional pump is connected to the material tank.

[0111] The bidirectional pump of the material dispensing equipment has all the technical solutions and effects of the aforementioned bidirectional pump, which will not be elaborated here.

[0112] It should be noted that in the actual manufacturing process, in order to process the first center hole M0, the switching device 22 first drills a hole along the axial direction from the end face of the end where the rotating rod 21 is set, and then uses some conventional sealing methods to seal the end of the hole near the rotating rod 21, thus finally forming the first center hole M0 in this invention.

[0113] It should be noted that, with Figure 13 For example, all of the above "first direction" refers to vertically downwards, and all "second direction" refers to vertically upwards.

[0114] As can be seen from the above description, the embodiments of the present invention achieve the following technical effects: In the first switching state of the switching device, the first piston slides along the first direction, and the material enters the first chamber. At the same time, the material in the second chamber is discharged from the first injection hole. In the second switching state of the switching device, the first piston slides along the second direction, and the material enters the second chamber. At the same time, the material in the first chamber is discharged from the second injection hole. In one switching state, one stroke of the first piston can simultaneously realize the injection and discharge of material. The injected material prepares for the next discharge, eliminating the need for a separate stroke to extract the material, thus saving time. When mixing color paste, the material is the color paste itself. The bidirectional pump of the present invention saves the time for extracting color paste and improves the color mixing efficiency.

[0115] Obviously, the embodiments described above are merely some, not all, embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort should fall within the scope of protection of the present invention.

[0116] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0117] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A bidirectional pump, characterized in that, include: The first cylinder (31) has a first inner cavity, and the bottom wall of the first cylinder (31) is provided with a first connecting hole (20b) and a second connecting hole (20d); The first piston (2) is located in the first inner cavity. The first piston (2) is in sliding sealing cooperation with the inner wall of the first cylinder (31). The first piston (2) divides the first inner cavity into a first cavity (31u) and a second cavity (31d). The first connecting hole (20b) and the second connecting hole (20d) are both connected to the second cavity (31d). A switching device (22) is provided with a first central hole (M0) and a second central hole (N0) that are not interconnected along the axial direction. The switching device (22) is provided with a first injection hole (N1), a second injection hole (N2) and a front through hole (N4) that are connected to the first central hole (M0) along the radial direction. The switching device (22) is provided with a rear through hole (N6) that is connected to the second central hole (N0) along the radial direction. The switching device (22) has a first switching state and a second switching state. The first circulation tube (32L) is connected to the first cavity (31u); as well as The second circulation tube (32R) is connected to the first cavity (31u); In the first switching state of the switching device (22), the front through hole (N4) is connected to the first connecting hole (20b), and the second circulation pipe (32R) is connected to the rear through hole (N6). In this state of the switching device (22), the first piston (2) slides along the first direction to compress the second chamber (31d). The material enters the first chamber (31u) sequentially from the second central hole (N0), the rear through hole (N6), and the second circulation pipe (32R). At the same time, the material in the second chamber (31d) is discharged sequentially from the second chamber (31d), the first connecting hole (20b), the front through hole (N4), the first central hole (M0), and the first injection hole (N1). In the second switching state of the switching device (22), the front through hole (N4) is connected to the first circulation pipe (32L), and the rear through hole (N6) is connected to the second connecting hole (20d). In this state of the switching device (22), the first piston (2) slides along the second direction to compress the first chamber (31u). The material enters the second chamber (31d) sequentially from the second central hole (N0), the rear through hole (N6), and the second connecting hole (20d). At the same time, the material in the first chamber (31u) is discharged sequentially from the first chamber (31u), the first circulation pipe (32L), the front through hole (N4), the first central hole (M0), and the second injection hole (N2).

2. The bidirectional pump according to claim 1, characterized in that, The bidirectional pump also includes a first housing (20), on which a discharge hole (3) is provided. The first housing (20) has an installation cavity communicating with the discharge hole (3). The first injection hole (N1), the second injection hole (N2), the front through hole (N4), the rear through hole (N6), the second cavity (31d), the first connecting hole (20b), the second connecting hole (20d), the first circulation pipe (32L), and the second circulation pipe (32R) are all communicating with the installation cavity. The switching device (22) is in a sealed and movable fit with the inner wall of the installation cavity. In the first switching state of the switching device (22), the first injection hole (N1) is communicating with the discharge hole (3). In the second switching state of the switching device (22), the second injection hole (N2) is communicating with the discharge hole (3).

3. The bidirectional pump according to claim 2, characterized in that, The switching device (22) has a third injection hole (N3) that communicates with the first central hole (M0) in the radial direction. The diameter of the third injection hole (N3) is smaller than the diameter of the first injection hole (N1) and the diameter of the second injection hole (N2). The switching device (22) has a third switching state. In the third switching state of the switching device (22), the third injection hole (N3) communicates with the discharge hole (3).

4. The bidirectional pump according to claim 3, characterized in that, The bidirectional pump also includes: The second cylinder has a second inner cavity (20c); The second piston (6) is capable of sliding and sealing with the second cylinder, and the second inner cavity (20c) communicates with the second cavity (31d); and The piston rod (1) is slidably disposed relative to the first inner cavity and the second inner cavity (20c), and the first piston (2) and the second piston (6) are both connected to the piston rod (1); The switching device (22) has a central through hole (N5) that communicates with the first central hole (M0) in a radial direction. In the first switching state or the third switching state of the switching device (22), the second inner cavity (20c) communicates with the first central hole (M0) through the central through hole (N5).

5. The bidirectional pump according to claim 4, characterized in that, The bidirectional pump also includes a third circulation pipe (32K), which is connected to the first cavity (31u). In the first switching state or the third switching state of the switching device (22), the third circulation pipe (32K) is connected to the second central hole (N0) through the rear through hole (N6).

6. The bidirectional pump according to claim 5, characterized in that, The rear through hole (N6) is configured as multiple. In the first switching state of the switching device (22), the front through hole (N4) is connected to the first connecting hole (20b), the middle through hole (N5) is connected to the second inner cavity (20c), and the second circulation pipe (32R) and the third circulation pipe (32K) are connected to the rear through hole (N6) one by one. In the second switching state of the switching device (22), the front through hole (N4) is connected to the first circulation pipe (32L), the middle through hole (N5) is connected to the second inner cavity (20c), and the second circulation pipe (32R) and the third circulation pipe (32K) are connected to the rear through hole (N6) one by one. The two connecting holes (20d) and the second inner cavity (20c) are connected to the same rear through hole (N6); in the third switching state of the switching device (22), the middle through hole (N5) is connected to the second inner cavity (20c), the second connecting hole (20d), the second circulation pipe (32R) and the third circulation pipe (32K) are connected to the rear through hole (N6) one by one, and the second connecting hole (20d) and the second inner cavity (20c) are connected to the same rear through hole (N6).

7. The bidirectional pump according to claim 5, characterized in that, The bidirectional pump also includes a return pipe (28) which is connected to the mounting cavity. The switching device (22) has a fourth switching state, a fifth switching state, and a sixth switching state. In the fourth switching state of the switching device (22), the first injection hole (N1) is connected to the return pipe (28). In the fifth switching state of the switching device (22), the second injection hole (N2) is connected to the return pipe (28). In the sixth switching state of the switching device (22), the third injection hole (N3) is connected to the return pipe (28).

8. The bidirectional pump according to claim 7, characterized in that, The rear through hole (N6) is configured as multiple. In the fourth switching state of the switching device (22), the front through hole (N4) is connected to the first connecting hole (20b), the middle through hole (N5) is connected to the second inner cavity (20c), and the second circulation pipe (32R) is connected to the rear through hole (N6) one by one. In the fifth switching state of the switching device (22), the front through hole (N4) is connected to the first circulation pipe (32L), and the middle through hole (N5) is connected to the second inner cavity (20c). The two connecting holes (20d) and the second inner cavity (20c) are connected to the same rear through hole (N6); in the sixth switching state of the switching device (22), the middle through hole (N5) is connected to the second inner cavity (20c), the second connecting hole (20d), the second circulation pipe (32R) and the third circulation pipe (32K) are connected to the rear through hole (N6) one by one, and the second connecting hole (20d) and the second inner cavity (20c) are connected to the same rear through hole (N6).

9. The bidirectional pump according to claim 7, characterized in that, The front through hole (N4) includes a first front through hole and a second front through hole, and the axis of the first front through hole and the axis of the second front through hole are located on a first straight line; The central through hole (N5) includes a first central through hole, a second central through hole, a third central through hole, and a fourth central through hole. The axis of the first central through hole and the axis of the second central through hole are located on a second straight line, and the axis of the third central through hole and the axis of the fourth central through hole are located on a third straight line. The rear through hole (N6) includes a first rear through hole, a second rear through hole, a third rear through hole, and a fourth rear through hole. The axis of the first rear through hole and the axis of the second rear through hole are located on a fourth straight line, and the axis of the third rear through hole and the axis of the fourth rear through hole are located on a fifth straight line.

10. The bidirectional pump according to claim 9, characterized in that, The first straight line is parallel to the second straight line, the second straight line is at an angle of 60° to the third straight line, the third straight line is parallel to the fourth straight line, the fourth straight line is at an angle of 60° to the fifth straight line, the switching device (22) is in rotational sealing cooperation with the mounting cavity, and the rotation angle of the switching device (22) in the first switching state, the second switching state, the third switching state, the fourth switching state, the fifth switching state and the sixth switching state differs by 60° in sequence.

11. The bidirectional pump according to any one of claims 4 to 10, characterized in that, The axes of the first injection hole (N1), the second injection hole (N2), and the third injection hole (N3) are located in a first plane, the axis of the front through hole (N4) is located in a second plane, the axis of the middle through hole (N5) is located in a third plane, and the axis of the rear through hole (N6) is located in a fourth plane. The first plane, the second plane, the third plane, and the fourth plane are parallel to each other and are arranged sequentially along the axial direction of the switching device (22).

12. The bidirectional pump according to any one of claims 5 to 10, characterized in that, The bidirectional pump also includes a second housing (11), which has a circulation channel. The first circulation pipe (32L), the second circulation pipe (32R), and the third circulation pipe (32K) are all connected to the first cavity (31u) through the circulation channel.

13. The bidirectional pump according to any one of claims 5 to 10, characterized in that, The first housing (20) has a first connecting channel (20g), a second connecting channel (20f) and a third connecting channel (20h). The first circulation pipe (32L) is connected to the mounting cavity through the first connecting channel (20g), the second circulation pipe (32R) is connected to the mounting cavity through the second connecting channel (20f), and the third circulation pipe (32K) is connected to the mounting cavity through the third connecting channel (20h).

14. A material dispensing device, characterized in that, It includes a material tank and a bidirectional pump as described in any one of claims 1 to 13, wherein the second central hole (NO) of the bidirectional pump is in communication with the material tank.

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