Pump body of plunger pump and plunger pump thereof

Abstract

The utility model discloses a pump body of a plunger pump and the plunger pump. The pump body comprises a pump body made of plastic and an inner core made of metal. The metal inner core is arranged at the proper position of the pump body, so that the pressure bearing capacity of the pump body is improved, and the weight and the manufacturing cost of the pump body are lower than those of a pump body made of pure metal materials.

Description

Technical Field

[0001] The utility model relates to the technical field of power tools, in particular to airless spraying equipment. Background Art

[0002] Airless spraying relies on a pump to apply high pressure to the paint, so that the paint is ejected and atomized from the liquid spraying component under high pressure without the aid of compressed air atomization. Most of the existing high-pressure airless spraying equipment uses a plunger pump to increase the pressure of the paint, and the material of the pump body, which is an important pressure-bearing component, is plastic. With the wide application of handheld and backpack high-pressure airless spraying equipment, in order to ensure the safety of use, the requirements for the pressure-bearing capacity of the plunger pump body are getting higher and higher. It is difficult for the existing plastic pump body to pass the pressure-bearing safety test. If a pump body made of pure metal is used, although it can meet the strict test requirements, it will greatly increase the manufacturing cost and the weight of the product.

[0003] In addition, the reciprocating movement of the plunger will cause pulsating supply of the spraying liquid, resulting in uneven injection pressure and flow rate, decreased fineness and uniformity of particles during the atomization process, and decreased compactness and adhesion after covering, thus reducing the spraying quality. Summary of the Invention

[0004] The technical problem to be solved by the utility model is to provide a pump body and its plunger pump with strong pressure-bearing capacity, light weight and low manufacturing cost.

[0005] Another technical problem to be solved by the utility model is to provide a plunger pump with more stable spraying pressure.

[0006] According to a first aspect of the present utility model, there is provided a pump body of a plunger pump. The pump body includes a pump body main body and an inner core. The material of the pump body main body is plastic, and the material of the inner core is metal. The inner core is integrally connected to the pump body main body. The pump body main body is provided with a main through hole, a liquid inlet interface hole for installing a liquid inlet valve and a liquid inlet joint, a protection valve interface hole for installing a pressure protection valve, and a return valve interface hole for installing a return valve. The main through hole extends along the axial direction of the pump body and penetrates the end faces at both axial ends of the pump body. The main through hole is respectively communicated with the liquid inlet valve interface hole, the protection valve interface hole, and the return valve interface hole. The first end of the main through hole is used for installing a liquid outlet joint, and the second end of the main through hole is used for installing a plunger rod assembly. The inner core includes an inner core main body having an axial through hole, a liquid inlet valve interface pipe portion, a pressure protection valve interface pipe portion, and a return valve joint portion. The liquid inlet valve interface pipe portion, the pressure protection valve interface pipe portion, and the return valve joint portion are respectively connected to the inner core main body. The liquid inlet valve interface pipe portion has a central hole extending along the axial direction, and the central hole of the liquid inlet valve interface pipe portion is communicated with the axial through hole of the inner core main body. The pressure protection valve interface pipe portion and the return valve joint portion are respectively provided with central through holes communicating with the axial through hole of the inner core main body. The inner core main body is disposed in the main through hole. The liquid inlet valve interface pipe portion extends into the liquid inlet valve interface hole, the pressure protection valve interface pipe portion extends into the protection valve interface hole, and the return valve joint portion extends into the return valve interface hole.

[0007] According to a second aspect of the present utility model, there is provided a plunger pump, including a liquid inlet joint, a liquid outlet joint, a plunger rod assembly, a liquid inlet valve, a liquid outlet valve, a pressure protection valve, a return valve, and the aforementioned pump body. The plunger rod assembly includes a plunger rod. The liquid inlet valve includes a liquid inlet valve seat, a liquid inlet valve core, and a liquid inlet valve core spring. The liquid outlet valve is installed at the tail end of the liquid outlet joint. The liquid inlet joint is installed in the liquid inlet interface hole. The liquid inlet valve seat is installed between the liquid inlet joint and the liquid inlet valve interface pipe portion. The liquid inlet valve core and the liquid inlet valve core spring are installed in the central hole of the liquid inlet valve interface pipe portion. The liquid inlet valve core spring respectively abuts against the liquid inlet valve core and the liquid inlet valve interface pipe portion. The liquid outlet joint is installed at the first end of the main through hole, and the tail end of the liquid outlet joint extends into the first end of the axial through hole of the inner core main body. The liquid outlet channel of the liquid outlet joint is respectively communicated with the central through holes of the pressure protection valve interface pipe portion and the return valve joint portion. The plunger rod assembly is installed at the second end of the main through hole, and one end of the plunger rod extends into the second end of the axial through hole of the inner core main body. The pressure protection valve is installed in the protection valve interface hole, and one end of the pressure protection valve extends into the pressure protection valve interface pipe portion. The return valve is installed in the return valve interface hole and is adjacent to the return valve joint portion.

[0008] The above-mentioned plunger pump, wherein the pump body has a pressure-stabilizing valve interface hole, which is connected to the main through hole; the inner core is provided with a pressure-stabilizing valve interface ring connected to the inner core body, the pressure-stabilizing valve interface ring extends into the pressure-stabilizing valve interface hole, and the center hole of the pressure-stabilizing valve interface ring is connected to the liquid outlet channel of the liquid outlet joint; the plunger pump includes a pressure-stabilizing valve, and the pressure-stabilizing valve includes a pressure-stabilizing valve housing, a pressure-stabilizing valve elastic element and a pressure-stabilizing valve spool; the pressure-stabilizing valve housing is connected to the pressure-stabilizing valve interface hole, the pressure-stabilizing valve housing has an inlet and an inner cavity, and the inlet is respectively connected to the center hole and the inner cavity of the pressure-stabilizing valve interface ring; the pressure-stabilizing valve elastic element is fixed in the inner cavity, dividing the inner cavity into a first chamber and a second chamber that are sealed from each other, the first chamber is close to the inlet, and the second chamber is an inflation chamber; the pressure-stabilizing valve spool includes a valve stem and a valve disc, the upper part of the valve stem extends into the inlet, and the bottom end of the valve stem is connected to the valve disc; the valve disc abuts the pressure-stabilizing valve elastic element to close or open the inlet.

[0009] The utility model has at least the following advantages:

[0010] 1. The pump body of the embodiment of the utility model is composed of a pump body made of plastic material and an inner core made of metal material. By arranging the metal inner core at an appropriate position of the pump body, the pressure bearing capacity of the pump body is improved, and the weight and manufacturing cost are lower than the pump body made of pure metal material;

[0011] 2. The pressure-stabilizing valve of the embodiment of the present invention has the function of stabilizing the spraying pressure of the plunger pump. When the plunger pump is in the second half of the cycle and increases the paint pressure to high pressure and delivers it to the spray gun through the liquid outlet connector, the liquid in the liquid outlet channel will flow into the pressure-stabilizing valve and push the pressure-stabilizing valve core to overcome the elastic force of the pressure-stabilizing valve elastic element and move toward the inner cavity of the shell, thereby opening the inlet and allowing the liquid to enter the first chamber of the pressure-stabilizing valve shell. When the plunger pump is in the first half of the cycle and only takes in liquid but does not spray, the pressure-stabilizing valve elastic element pushes the pressure-stabilizing valve core to reset and reclose the inlet. During this period, the liquid in the first chamber flows to the spray gun through the inlet and liquid outlet channel of the pressure-stabilizing valve shell in turn. In this way, the injection pressure and flow of the plunger pump are more balanced, the density and adhesion of the spray liquid after coverage are improved, and better spraying and spraying effects can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 and Figure 2 A three-dimensional schematic diagram and a top schematic diagram of a plunger pump according to another embodiment of the utility model are respectively shown.

[0013] Figure 3 Shown Figure 2 BB cross-section diagram.

[0014] Figure 4 Shown Figure 3 AA cross-sectional diagram of .

[0015] Figure 5 The three-dimensional schematic diagram of the pump body of a plunger pump according to an embodiment of the present invention is shown.

[0016] Figure 6 The three-dimensional schematic diagram of the metal inner core of a plunger pump according to an embodiment of the present invention is shown.

[0017] Figure 7 The cross-sectional schematic diagram of the pump body of a plunger pump according to an embodiment of the present invention is shown. Detailed implementation manners

[0018] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0019] Please refer to Figures 1 to 7 . A plunger pump according to an embodiment of the present invention includes a pump body 1, a liquid inlet joint 21, a liquid outlet joint 22, a plunger rod assembly 3, a liquid inlet valve 41, a liquid outlet valve 42, a pressure protection valve 5, and a return valve 6.

[0020] The pump body 1 includes a pump body main body 1a and an inner core 1b. The material of the pump body main body 1a is plastic, and the material of the inner core 1b is metal. The inner core 1b is integrally connected to the pump body main body 1a. The above-mentioned metal includes, but is not limited to, metal materials such as stainless steel. Preferably, the pump body main body 1a and the inner core 1b are integrally formed by in-mold injection molding.

[0021] The pump body main body 1a is provided with a main through hole 110, a liquid inlet interface hole 111 for installing the liquid inlet valve 41 and the liquid inlet joint 21, a protection valve interface hole 112 for installing the pressure protection valve 5, and a return valve interface hole 113 for installing the return valve 6. The main through hole 110 extends along the axial direction of the pump body main body and penetrates the end faces at both axial ends of the pump body main body. The main through hole 110 is respectively communicated with the liquid inlet valve interface hole 111, the protection valve interface hole 112, and the return valve interface hole 113. The first end of the main through hole 110 is used for installing the liquid outlet joint 22, and the second end of the main through hole 110 is used for installing the plunger rod assembly 3.

[0022] The inner core 1b includes an inner core main body 120 having an axial through hole 1200, a liquid inlet valve interface pipe portion 121, a pressure protection valve interface pipe portion 122, and a return valve connection portion 123. The liquid inlet valve interface pipe portion 121, the pressure protection valve interface pipe portion 122, and the return valve connection portion 123 are respectively connected to the inner core main body 120. The liquid inlet valve interface pipe portion 121 has a central hole 1210 extending along the axial direction, and the central hole 1210 of the liquid inlet valve interface pipe portion 121 is communicated with the axial through hole 1200 of the inner core main body; specifically, an opening (not shown in the figure) communicating the central hole 1210 and the axial through hole 1200 is provided on the bottom wall 1211 of the central hole 1210. The pressure protection valve interface pipe portion 122 and the return valve connection portion 123 are respectively provided with central through holes communicating with the axial through hole 1200 of the inner core main body.

[0023] The inner core body 120 is disposed within the main through hole 110. The liquid inlet valve interface pipe portion 121 extends into the liquid inlet valve interface hole 111, the pressure protection valve interface pipe portion 122 extends into the protection valve interface hole 112, and the return valve connection portion 123 extends into the return valve interface hole 113.

[0024] The liquid inlet joint 21 is installed in the liquid inlet interface hole 111. The liquid inlet valve 41 includes a liquid inlet valve seat 411, a liquid inlet valve core 412, and a liquid inlet valve core spring 413. The liquid inlet valve seat 411 is installed between the liquid inlet joint 21 and the liquid inlet valve interface pipe portion 121. The liquid inlet valve core 412 and the liquid inlet valve core spring 413 are installed in the central hole 1210 of the liquid inlet valve interface pipe portion. The liquid inlet valve core spring 413 abuts against the liquid inlet valve core 412 and the liquid inlet valve interface pipe portion 121 respectively.

[0025] The liquid outlet joint 22 is installed at the first end of the main through hole 110. The liquid outlet valve 42 is installed at the tail end of the liquid outlet joint 22. The liquid outlet valve 42 includes a liquid outlet valve seat 421, a liquid outlet valve core 422, and a liquid outlet valve core spring 423. The tail end of the liquid outlet joint 22 extends into the first end of the axial through hole 1200 of the inner core body. The liquid outlet channel 220 of the liquid outlet joint 22 communicates with the central through holes of the pressure protection valve interface pipe portion 122 and the return valve connection portion 123 respectively.

[0026] The plunger rod assembly 3 is installed at the second end of the main through hole 110. The plunger rod assembly 3 includes a plunger rod 31, a bushing assembly, a seal ring seat 33, and a seal ring 34. The bushing assembly and the seal ring seat 34 are respectively sleeved outside the plunger rod 31. The bushing assembly is connected to the second end of the main through hole 110. The seal ring 34 is sleeved outside the seal ring seat 33 and abuts against the seal ring seat 33 and one end of the inner core body 120 close to the plunger pump assembly respectively. The aforementioned bushing assembly includes an inner bushing 321 and an outer bushing 322. One end of the plunger rod 31 extends into the second end of the axial through hole 1200 of the inner core body.

[0027] The pressure protection valve 5 is installed in the protection valve interface hole 112. One end of the pressure protection valve 5 extends into the pressure protection valve interface pipe portion 122. The pressure protection valve 5 includes a protection valve housing 51, a protection valve core 52, and a protection valve spring 53. The protection valve spring 53 abuts against the protection valve core 52 and the protection valve housing 51 respectively. When the spraying liquid flowing out from the central through hole of the pressure protection valve interface pipe portion 122 is greater than the elastic force of the protection valve spring 53, the protection valve core 52 moves and pops out to trigger an external micro switch.

[0028] The reflux valve 6 is installed in the reflux valve interface hole 113 and is adjacent to the reflux valve joint part 123. The reflux valve 6 includes a reflux valve seat 61, a reflux valve core 62, a reflux valve spring 63, a reflux valve installation joint 64, and a reflux valve seat bushing 65. The two ends of the reflux valve spring 63 respectively abut against the reflux valve core 62 and the reflux valve installation joint 64. The reflux valve installation joint 64 is connected to the pump body main body 1a. The reflux valve seat bushing 65 is connected to the hole wall of the reflux valve interface hole 113 and abuts against one end of the reflux valve seat 61, and the other end of the reflux valve seat 61 abuts against the reflux valve joint part 123. When the reflux valve 6 is in the closed state, the reflux valve core 62 closes the valve port of the reflux valve seat 61 under the elastic force of the reflux valve spring 63. When the pressure of the spraying liquid flowing out from the central through hole of the reflux valve joint part 123 is greater than the elastic force of the reflux valve spring 63, the reflux valve core 62 moves and opens the valve port. A reflux valve liquid outlet 1131 is provided on the side wall of the reflux valve interface hole 113.

[0029] Further, the plunger pump further includes a pressure stabilizing valve 7. The pump body main body 1a is provided with a pressure stabilizing valve interface hole 114 for installing the pressure stabilizing valve 7, and the pressure stabilizing valve interface hole 114 communicates with the main through hole 110. The inner core 1b is provided with a pressure stabilizing valve interface ring part 124 connected to the inner core main body 120, and the pressure stabilizing valve interface ring part 124 extends into the pressure stabilizing valve interface hole 114. The central hole of the pressure stabilizing valve interface ring part 124 communicates with the axial through hole of the inner core main body 120 and the liquid outlet channel 220 of the liquid outlet joint 22.

[0030] The pressure stabilizing valve 7 includes a pressure stabilizing valve housing 71, a pressure stabilizing valve elastic element 72, and a pressure stabilizing valve core 73. The pressure stabilizing valve housing 71 is screwed to the pressure stabilizing valve interface hole 114. The pressure stabilizing valve housing 71 has an inlet 711 and an inner cavity 712. The inlet 711 communicates with the central hole of the pressure stabilizing valve interface ring part 124 and the inner cavity 712 respectively. The pressure stabilizing valve elastic element 72 is fixed in the inner cavity 712, dividing the inner cavity 712 into a first chamber 7121 and a second chamber 7122 that are hermetically sealed from each other. The first chamber 7121 is close to the inlet 711, and the second chamber 7122 is an air-filled chamber. Optionally, nitrogen is filled in the second chamber 7122. An air inflation through hole 7123 is provided on the inner wall of the second chamber 7122, and a sealing element is provided in the air inflation through hole 7123. The sealing element is detachably connected to the pressure stabilizing valve housing 71. Specifically, the air inflation through hole 7123 is a threaded through hole; the sealing element includes a screw 75, and the screw 75 is screwed to the air inflation through hole 7123. Optionally, the screw 75 is a self-tapping screw.

[0031] In this embodiment, the material of the pressure stabilizing valve elastic element 72 is a non-metallic material, such as rubber. The initial shape of the pressure stabilizing valve elastic element 72 is approximately sheet-shaped. After the product is assembled, nitrogen is filled into the second chamber 7122 from the air inflation through hole 7123, and then the screw 75 is tightened. After the nitrogen is filled, it will support the pressure stabilizing valve elastic element 72, and then push up the pressure stabilizing valve core 73.

[0032] In this embodiment, the pressure stabilizing valve housing 71 includes an upper housing 71a and a lower housing 71b. The upper housing 71a and the lower housing 71b are detachably connected and jointly define an inner cavity 712. Among them, the upper housing 71a includes a narrow neck 713 and a wide body 714. The bottom end of the neck 713 is connected to the top of the body 714. The central through hole of the neck 713 constitutes the aforementioned inlet 711. An external thread 7141 is provided on the outer side of the bottom of the body 714. An internal thread 7151 that cooperates with the external thread 7141 is provided on the inner side of the top of the lower housing 71b. The bottom of the upper housing 71a extends into the lower housing 71b and is screwed to the lower housing 71b. A step 716 is provided on the inner wall of the lower housing 71b. The pressure stabilizing valve elastic element 72 after being propped up has a top wall 721 and a side wall portion 722 extending downward from the periphery of the top wall 721. An annular flange 723 extending radially outward is provided at the bottom end of the side wall portion 722. The annular flange 723 is clamped between the bottom of the upper housing 71a and the step 716 of the lower housing 71b.

[0033] The pressure stabilizing valve spool 73 includes a valve stem 731 and a valve disc 732. The upper part of the valve stem 731 extends into the inlet 711, and the bottom end of the valve stem 731 is connected to the valve disc 732. The valve disc 732 abuts against the pressure stabilizing valve elastic element 72 to close or open the inlet 711. Preferably, a first conical surface is provided on the top of the valve disc 732, and a second conical surface that forms a sealing fit with the first conical surface is provided at a position adjacent to the inlet 711 in the inner cavity 712.

[0034] Furthermore, the pressure stabilizing valve 7 further includes a guide sleeve 77. The guide sleeve 77 is arranged in the inlet 711 of the pressure stabilizing valve housing, and the top of the valve stem 731 extends into the guide sleeve 77. Specifically, the guide sleeve 77 is in the shape of a hollow cylinder, and a circumferential annular flange 771 extending radially is provided at the top of the guide sleeve 77. The guide sleeve 77 extends into the inlet 711, and the annular flange 771 presses on the top surface of the pressure stabilizing valve housing.

[0035] Preferably, the pressure stabilizing valve 7 further includes a valve stem spring 74. A spring stop portion 772 is provided on the inner wall of the guide sleeve 77; the valve stem spring 74 is sleeved outside the rod body of the valve stem 731 and abuts against the spring stop portion 772 and the valve disc 732 respectively. The provision of the valve stem spring 74 helps to assist in judging whether the inflation is in place during the inflation process of the second chamber 7122.

[0036] In each reciprocating motion cycle (i.e., cycle period) of the plunger pump, liquid is introduced in the first half of the cycle but not sprayed, and spraying is carried out in the second half of the cycle but no liquid is introduced, and this cycle repeats. Since spraying operation is not carried out in half of each cycle period, it results in unbalanced injection pressure and flow rate, and low spraying efficiency. After installing the pressure stabilizing valve, when the plunger pump is in the second half of the cycle period and the plunger pump increases the coating to high pressure and transports it to the spray gun through the liquid outlet channel 220 of the liquid outlet joint 22, the pressure stabilizing valve spool 73, under the action of the liquid pressure flowing into the inlet 711, overcomes the elastic force of the pressure stabilizing valve elastic element 72 and opens the inlet 711, allowing the liquid to flow into the first chamber 7121. When the reciprocating pump is in the first half of the cycle period and the plunger pump only introduces liquid but does not spray, the elastic force exerted by the pressure stabilizing valve elastic element 72 on the pressure stabilizing valve spool 73 is greater than the liquid pressure in the inlet 711, and the pressure stabilizing valve spool 73 is reset by the pressure stabilizing valve elastic element 72, causing the liquid in the first chamber 7121 to flow to the spray gun successively through the inlet 711 of the pressure stabilizing valve housing and the liquid outlet channel 220.

[0037] In this embodiment, the liquid inlet interface hole 111 and the pressure stabilizing valve interface hole 114 are respectively arranged at the top and bottom of the pump body main body 1a, and the protection valve interface hole 112 and the return valve interface hole 113 are respectively arranged on two opposite sides of the pump body main body 1a. Internal threads are respectively provided at the first end and the second end of the main through hole 110, the outer end hole of the liquid inlet interface hole 111, the outer end hole of the protection valve interface hole 112, the hole body of the return valve interface hole 113, and the hole body of the pressure stabilizing valve interface hole 114. The liquid inlet joint 21, the liquid outlet joint 22, the outer bushing 322, the protection valve shell 51, the return valve seat bushing 65, and the pressure stabilizing valve housing 71 are respectively screwed to the outer end hole of the liquid inlet interface hole 111, the first end of the main through hole 110, the second end of the main through hole 110, the outer end hole of the protection valve interface hole 112, the hole body of the return valve interface hole 113, and the hole body of the pressure stabilizing valve interface hole 114.

[0038] In this embodiment, the inner core body 120 includes a first cylindrical part 131, a second cylindrical part 132, and a connecting pipe part 133; the first cylindrical part 131 includes a first bottom wall 1311 and a first annular side wall 1312 connected to the periphery of the first bottom wall 1311, the second cylindrical part 132 includes a second bottom wall 1321 and a second annular side wall 1322 connected to the periphery of the second bottom wall 1321, the connecting pipe part 133 is connected between the first bottom wall 1311 and the second bottom wall 1321, and the connecting pipe part 133 is thinner than the first cylindrical part 131 and the second cylindrical part 132, which helps to increase the pressure and at the same time increases the pressure resistance of the parts. The top of the first cylindrical part 131 faces the first end of the main through hole 110 for the tail end of the liquid outlet joint 22 to extend in, and the top of the second cylindrical part 132 faces the second end of the main through hole 110 for one end of the plunger rod 31 of the plunger rod assembly to extend in. During operation, the spraying liquid flowing out of the central hole 1210 of the liquid inlet valve interface pipe part 121 enters between one end of the plunger rod 31 and the second bottom wall 1321. The pressure protection valve interface pipe part 122, the return valve joint part 123, and the pressure stabilizing valve interface ring part 124 are respectively connected to the first annular side wall 1312, and the liquid inlet valve interface pipe part 121 is connected to the second annular side wall 1322.

[0039] Further, annular flanges protruding radially are respectively provided at the top ends of the second annular side wall 1322, the pressure protection valve interface pipe part 122, and the return valve joint part 123.

[0040] The pump body of the embodiment of the present utility model is composed of a pump body main body made of plastic material and an inner core made of metal material. By arranging a metal inner core at an appropriate position of the pump body, the bursting strength of the pump body is close to that of a pure metal pump body, and the bursting pressure reaches 130 Mpa, while the weight and manufacturing cost are both lower than those of the pump body made of pure metal material.

[0041] Obviously, those skilled in the art can make various changes and modifications to the present utility model without departing from the spirit and scope of the present utility model. Thus, if these modifications and variations of the present utility model fall within the scope of the claims of the present utility model and its equivalent technologies, the present utility model is also intended to include these changes and modifications.

Claims

1. A pump body of a plunger pump, characterized in that, The pump body includes a pump body main body and an inner core. The material of the pump body main body is plastic, and the material of the inner core is metal. The inner core is integrally connected to the pump body main body. The pump body main body is provided with a main through hole, a liquid inlet interface hole for installing a liquid inlet valve and a liquid inlet joint, a protection valve interface hole for installing a pressure protection valve, and a return valve interface hole for installing a return valve. The main through hole extends along the axial direction of the pump body and penetrates the end faces at both axial ends of the pump body. The main through hole is respectively communicated with the liquid inlet valve interface hole, the protection valve interface hole, and the return valve interface hole. The first end of the main through hole is used for installing a liquid outlet joint, and the second end of the main through hole is used for installing a plunger rod assembly. The inner core includes an inner core main body having an axial through hole, a liquid inlet valve interface pipe portion, a pressure protection valve interface pipe portion, and a return valve joint portion. The liquid inlet valve interface pipe portion, the pressure protection valve interface pipe portion, and the return valve joint portion are respectively connected to the inner core main body. The liquid inlet valve interface pipe portion has a central hole extending along the axial direction, and the central hole of the liquid inlet valve interface pipe portion is communicated with the axial through hole of the inner core main body. The pressure protection valve interface pipe portion and the return valve joint portion are respectively provided with central through holes communicated with the axial through hole of the inner core main body. The inner core main body is arranged in the main through hole; the liquid inlet valve interface pipe portion extends into the liquid inlet valve interface hole, the pressure protection valve interface pipe portion extends into the protection valve interface hole, and the return valve joint portion extends into the return valve interface hole.

2. The pump body according to claim 1, characterized in that, The pump body main body has a pressure stabilizing valve interface hole for installing a pressure stabilizing valve, and the pressure stabilizing valve interface hole is communicated with the main through hole. The inner core is provided with a pressure stabilizing valve interface ring portion connected to the inner core main body. The pressure stabilizing valve interface ring portion extends into the pressure stabilizing valve interface hole, and the central hole of the pressure stabilizing valve interface ring portion is communicated with the axial through hole of the inner core main body.

3. The pump body according to claim 2, wherein, Internal threads are respectively provided at the first end and the second end of the main through hole, the outer end hole of the liquid inlet interface hole, the outer end hole of the protection valve interface hole, the hole body of the return valve interface hole, and the hole body of the pressure stabilizing valve interface hole.

4. The pump body according to claim 2, characterized in that, The liquid inlet interface hole and the pressure stabilizing valve interface hole are respectively arranged at the top and the bottom of the pump body main body, and the protection valve interface hole and the return valve interface hole are respectively arranged on two opposite sides of the pump body main body.

5. The pump body according to claim 2, wherein, The inner core main body includes a first cylindrical portion, a second cylindrical portion, and a connecting pipe portion; the first cylindrical portion includes a first bottom wall and a first annular side wall connected to the periphery of the first bottom wall, the second cylindrical portion includes a second bottom wall and a second annular side wall connected to the periphery of the second bottom wall, the connecting pipe portion is connected between the first bottom wall and the second bottom wall, and the connecting pipe portion is thinner than the first cylindrical portion and the second cylindrical portion; the top of the first cylindrical portion faces the first end of the main through hole for the tail end of the liquid outlet joint to extend into, and the top of the second cylindrical portion faces the second end of the main through hole for one end of the plunger rod of the plunger rod assembly to extend into. The pressure protection valve interface pipe portion, the return valve joint portion, and the pressure stabilizing valve interface ring portion are respectively connected to the first annular side wall, and the liquid inlet valve interface pipe portion is connected to the second annular side wall.

6. The pump body according to claim 5, wherein Annular flanges protruding radially are respectively provided at the top ends of the second annular side wall, the pressure protection valve interface pipe portion, and the return valve joint portion.

7. The pump body according to claim 1, characterized in that, The pump body main body and the inner core are integrally formed by in-mold injection molding.

8. A plunger pump, comprising a liquid inlet joint, a liquid outlet joint, a plunger rod assembly, a liquid inlet valve, a liquid outlet valve, a pressure protection valve and a reflux valve; the plunger rod assembly includes a plunger rod, the liquid inlet valve includes a liquid inlet valve seat, a liquid inlet valve core and a liquid inlet valve core spring; the liquid outlet valve is installed at the tail end of the liquid outlet joint; characterized in that, The plunger pump includes the pump body as described in Claim 1; The liquid inlet joint is installed in the liquid inlet interface hole, the liquid inlet valve seat is installed between the liquid inlet joint and the liquid inlet valve interface pipe part, the liquid inlet valve core and the liquid inlet valve core spring are installed in the central hole of the liquid inlet valve interface pipe part, and the liquid inlet valve core spring abuts against the liquid inlet valve core and the liquid inlet valve interface pipe part respectively; The liquid outlet joint is installed at the first end of the main through hole, and the tail end of the liquid outlet joint extends into the first end of the axial through hole of the inner core body. The liquid outlet channels of the liquid outlet joint are respectively communicated with the central through holes of the pressure protection valve interface pipe part and the return valve joint part; The plunger rod assembly is installed at the second end of the main through hole, and one end of the plunger rod extends into the second end of the axial through hole of the inner core body; The pressure protection valve is installed in the protection valve interface hole, and one end of the pressure protection valve extends into the pressure protection valve interface pipe part; The return valve is installed in the return valve interface hole and is adjacent to the return valve joint part.

9. The plunger pump according to claim 8, characterized in that, The plunger rod assembly includes a bushing assembly, a seal ring seat and a seal ring. The bushing assembly and the seal ring seat are respectively sleeved outside the plunger rod. The bushing assembly is spirally connected to the second end of the main through hole. The seal ring is sleeved outside the seal ring seat and abuts against the seal ring seat and one end of the inner core body close to the plunger pump assembly respectively.

10. The plunger pump according to claim 8, characterized in that, The pump body main body has a pressure stabilizing valve interface hole, and the pressure stabilizing valve interface hole is communicated with the main through hole; the inner core is provided with a pressure stabilizing valve interface ring part connected to the inner core body, and the pressure stabilizing valve interface ring part extends into the pressure stabilizing valve interface hole. The central hole of the pressure stabilizing valve interface ring part is communicated with the liquid outlet channel of the liquid outlet joint; The plunger pump includes a pressure stabilizing valve, and the pressure stabilizing valve includes a pressure stabilizing valve housing, a pressure stabilizing valve elastic element and a pressure stabilizing valve core; The pressure stabilizing valve housing is connected to the pressure stabilizing valve interface hole. The pressure stabilizing valve housing has an inlet and an inner cavity. The inlet is respectively communicated with the central hole of the pressure stabilizing valve interface ring part and the inner cavity; the pressure stabilizing valve elastic element is fixed in the inner cavity, separating the inner cavity into a first chamber and a second chamber that are hermetically sealed from each other. The first chamber is close to the inlet, and the second chamber is an air-filled chamber; The pressure stabilizing valve core includes a valve stem and a valve disc. The upper part of the valve stem extends into the inlet, and the bottom end of the valve stem is connected to the valve disc; the valve disc abuts against the pressure stabilizing valve elastic element to close or open the inlet.

11. The plunger pump according to claim 10, characterized in that, An air inflation through hole is formed in the inner wall of the second chamber, and a sealing element is arranged in the air inflation through hole. The sealing element is detachably connected to the pressure stabilizing valve housing.

12. The plunger pump according to claim 10, characterized in that, The pressure stabilizing valve housing includes an upper shell and a lower shell. The upper shell and the lower shell are detachably connected and jointly define the inner cavity; The upper shell includes a narrow neck and a wide body. The bottom end of the neck is connected to the top of the body, and the central through hole of the neck constitutes the inlet.

13. The plunger pump according to claim 10, characterized in that, The material of the elastic element of the pressure stabilizing valve is a non-metallic material. The elastic element of the pressure stabilizing valve includes a top wall and a side wall portion extending downward from the periphery of the top wall. The bottom end of the side wall portion is provided with an annular flange extending radially outward, and the annular flange is clamped between the bottom of the upper shell and the top of the lower shell.

14. The plunger pump according to claim 10, characterized in that, The pressure stabilizing valve includes a guide sleeve, the guide sleeve is arranged in the inlet of the pressure stabilizing valve housing, and a spring stop portion is arranged on the inner wall of the guide sleeve; The top of the valve rod extends into the guide sleeve; the pressure stabilizing valve includes a valve rod spring, the valve rod spring is sleeved outside the rod body of the valve rod and abuts against the spring stop portion and the valve disc respectively.

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