Conveniently maintained pilot reversing valve for pneumatic double-diaphragm pump

Abstract

The utility model provides a pilot reversing valve convenient to maintain for a pneumatic double-diaphragm pump, which comprises a valve body, a left end cover, a right end cover, a first sliding sleeve, a second sliding sleeve, a sliding rod capable of sliding back and forth in the first sliding sleeve and the second sliding sleeve, a valve clack mounted on the sliding rod and sliding together with the sliding rod, and a reversing plate contacted with the valve clack to form plane sliding dynamic seal, the left feeler lever and the right feeler lever are respectively arranged on the left end cover and the right end cover; and a first chamber, a second chamber, and a third chamber for internal travel; the sliding rod is divided into two or more blocks in the length direction, and the length of each block is not larger than that of the reversing plate. When the quick-wear part is maintained, the diaphragm pump does not need to be disassembled from a liquid conveying line or completely disassembled from outside to inside, the sliding rod, the feeler lever and other parts can be taken out only by disassembling the reversing plate from the shell of the diaphragm pump, the disassembling process and the assembling process during maintenance are greatly simplified, and the maintenance efficiency is improved.

Description

Technical Field

[0001] This utility model belongs to the field of diaphragm pumps, and in particular relates to a pilot directional valve for a pneumatic double diaphragm pump that is easy to maintain. Background Technology

[0002] The pneumatic dual diaphragm pump is a new type of conveying machinery and one of the most innovative pump types in China. It uses compressed gas as its power source and can completely pump out various corrosive liquids, liquids containing particles, and high-viscosity, volatile, flammable, and highly toxic liquids. The working principle of the pneumatic dual diaphragm pump is as follows: the two air chambers of the diaphragm pump are continuously and alternately filled and discharged with compressed air, which drives the two liquid chambers of the diaphragm pump to alternately draw in and discharge liquid, thus achieving continuous pumping and conveying of liquid. The alternating filling and discharging of compressed air into the two air chambers of the diaphragm pump is achieved by the back-and-forth switching of the main air valve. The switching of the main air valve is initiated by a pilot directional valve that sends a switching signal to the main air valve. Upon receiving the switching signal from the pilot directional valve, the main air valve performs the switching.

[0003] The structure of a pilot-operated directional valve mainly includes a valve body, a valve sleeve, a sliding rod that slides back and forth within the sleeve, a valve disc, and a reversing plate mounted on the sliding rod. The sliding rod, valve disc, reversing plate, and some sealing rings are prone to damage during long-term reciprocating motion. A utility model patent with application number 201721041065.6 proposes a pilot-operated directional valve for a pneumatic double diaphragm pump, which improves component lifespan and reduces maintenance rate by using ceramic materials for the valve disc and reversing plate. However, due to the presence of easily damaged components such as sealing rings, there are still situations requiring downtime for maintenance. During maintenance, the diaphragm pump must first be disconnected from the infusion line, then the inlet and outlet pipes of the diaphragm pump must be disassembled, followed by the removal of the left and right fluid covers, and then the left and right diaphragms. Only after disassembling these components can the pilot-operated directional valve, located in the center of the diaphragm pump, be exposed. Afterwards, components such as the contact rod and end caps must be removed to allow for the removal and replacement of damaged components such as the sliding rod, valve disc, and seals. The disassembly process is complex and time-consuming, and the assembly process is equally time-consuming, which seriously affects the production process. Summary of the Invention

[0004] This invention addresses the technical problem of complex and time-consuming maintenance of pilot directional valves in existing pneumatic dual diaphragm pumps by proposing a pilot directional valve that allows for direct removal and replacement of internally damaged components without completely disassembling the diaphragm pump, via the air main valve.

[0005] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0006] A pilot-operated directional valve for a pneumatic double diaphragm pump that is easy to maintain includes a valve body, a left end cover and a right end cover installed at the left and right ends of the valve body, a first sliding sleeve and a second sliding sleeve installed in the valve body, a slide rod that can slide back and forth within the first sliding sleeve and the second sliding sleeve, a valve disc installed on the slide rod and sliding together with the slide rod, a directional plate that contacts the valve disc to form a planar sliding dynamic seal, and a left contact rod and a right contact rod respectively disposed on the left end cover and the right end cover; a first chamber formed by the left end cover, the inner hole of the first sliding sleeve, and the left side of the slide rod; a second chamber formed by the slide rod, the first sliding sleeve, the second sliding sleeve, the valve body, and the directional plate; and a third chamber formed by the right side of the slide rod, the inner hole of the second sliding sleeve, and the right end cover.

[0007] The slide bar is divided into two or more pieces along its length, and the length of each piece is no greater than the length of the reversing plate.

[0008] Preferably, the bottom of the second chamber is provided with a slide rail to support the slide rod.

[0009] Preferably, the slide bar comprises three parts: a left slide bar, a middle slide bar, and a right slide bar.

[0010] Preferably, the reversing plate is provided with a first working hole, an exhaust hole and a second working hole in sequence; the first chamber is provided with a first connecting hole and is connected to the first working hole; the third chamber is provided with a second connecting hole and is connected to the second working hole; the exhaust hole on the reversing plate is connected to the main exhaust hole of the diaphragm pump.

[0011] Preferably, the first chamber is located on the left side of the slide rod, and this chamber is connected to the first working hole on the reversing plate through the first connecting hole; the second chamber is connected to a compressed air source and is filled with compressed air; the third chamber is located on the right side of the slide rod, and this chamber is connected to the second working hole on the reversing plate through the second connecting hole; when the slide rod moves to a certain position under the push of the diaphragm, the first chamber and the third chamber located on the left and right sides of the slide rod, respectively, one of which is filled with compressed air and the other is filled with compressed air, and a pressure difference is quickly formed on the left and right sides of the slide rod, which pushes the slide rod to quickly change direction.

[0012] Preferably, the second working hole (or the first working hole) on the reversing plate is also connected to the control chamber of the air main valve of the diaphragm pump. As the pilot reversing valve reverses, the second working hole (or the first working hole) alternately fills and discharges compressed air into the control chamber of the air main valve, that is, sends a reversing signal to the air main valve to drive the air main valve to reverse.

[0013] Preferably, the valve disc and the reversing plate are made of ceramic material. The valve disc slides back and forth on the reversing plate under the drive of the slide rod, forming a planar sliding dynamic seal between the two.

[0014] Preferably, the slide bar is provided with a first Y-ring and a second Y-ring; the valve disc is provided with a concave hole.

[0015] Preferably, the slide rail is made of ceramic or POM material.

[0016] Compared with the prior art, the advantages and positive effects of this utility model are as follows:

[0017] This utility model's pilot-operated directional valve divides the slide rod into two or more pieces from left to right, with each piece's length being less than or equal to the length of the directional plate. The slide rod can be removed through the hole in the directional plate. When the seals or slide rod inside the pilot-operated directional valve are damaged, simply remove the air main valve and front cover, then remove the directional plate, remove the slide rod from the directional plate, and replace the damaged part. This process eliminates the need to disconnect the diaphragm pump from the infusion line or completely disassemble the diaphragm pump from the outside in, greatly simplifying the disassembly and assembly process during maintenance and significantly improving maintenance efficiency. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of the pneumatic double diaphragm pump of this utility model;

[0019] Figure 2 for Figure 1 A longitudinal sectional view;

[0020] Figure 3 This is a schematic diagram of the pilot-operated directional valve of this utility model;

[0021] In the above figures: 1-Valve body; 2-Left end cover; 3-Right end cover; 4-First sliding sleeve; 5-Second sliding sleeve; 6-Sliding rod; 61-Left sliding rod; 62-Middle sliding rod; 63-Right sliding rod; 7-Valve disc; 8-Reversing plate; 9-Left contact rod; 10-Right contact rod; 11-First Y-ring; 12-Second Y-ring; 13-Slide rail; 101-First chamber; 102-Second chamber; 103-Third chamber; 104-First working hole; 105-Exhaust hole; 106- Second working hole; 107-First connecting hole; 108-Second connecting hole; 109-Concave hole; 201-Water inlet pipe; 202-Left liquid chamber; 203-Left air chamber; 204-Left diaphragm; 205-Water outlet pipe; 206-Right air chamber; 207-Right diaphragm; 208-Right liquid chamber; 209-Air main valve; 210-Left fixing plate; 211, Right fixing plate; 212-Housing shell; 213-Left fluid cover; 214-Right fluid cover; 215-Front cover. Detailed Implementation

[0022] To better understand this utility model, the following detailed description is provided in conjunction with the accompanying drawings and embodiments.

[0023] Example: Figure 1 , Figure 2 As shown, the pilot-operated directional valve of this utility model is applied to a pneumatic double diaphragm pump. The pneumatic double diaphragm pump includes a housing 212, an inlet pipe 201, and an outlet pipe 205. A left fluid cover 213 and a right fluid cover 214 are installed at both ends of the housing 212. A front cover 215 is provided at the front end of the housing 212, and an air main valve 209 is installed on the front cover 215. A left diaphragm 204 and a right diaphragm 207 are installed inside the housing 212 through components such as a left fixed plate 210 and a right fixed plate 211, thereby dividing the internal space of the housing into a left liquid chamber 202, a left air chamber 203, a right air chamber 206, and a right liquid chamber 208. A pilot-operated directional valve is installed in the middle of the housing.

[0024] like Figure 3 As shown, the pilot directional valve includes a valve body 1 (part of the diaphragm pump housing), with a left end cap 2 and a right end cap 3 installed at its left and right ends, respectively. A first sliding sleeve 4 and a second sliding sleeve 5 are installed inside the valve body 1, along with a sliding rod 6 that can slide back and forth within the first sliding sleeve 4 and the second sliding sleeve 5. A valve disc 7 is mounted on the sliding rod 6 and slides together with it. A reversing plate 8 is installed on the valve body, and the valve disc 7 contacts the reversing plate 8 to form a planar sliding and sealing structure. A left contact rod 9 and a right contact rod 10 are respectively provided on the left and right end caps. These two contact rods can move axially under the push of the diaphragm assembly of the diaphragm pump, thereby pushing the sliding rod 6 to move. The pilot-operated directional valve travels through the following three chambers separated by various components: the first chamber 101 is formed by the left end cover 2, the inner hole of the first sliding sleeve 4, and the left side of the slide rod 6; the second chamber 102 is formed by the slide rod 6, the first sliding sleeve 4, the second sliding sleeve 5, the valve body 1, and the directional plate 8; and the third chamber 103 is formed by the right side of the slide rod 6, the inner hole of the second sliding sleeve 5, and the right end cover 3.

[0025] The slide bar 6 is divided into two or more pieces from left to right, and the length of each piece is less than or equal to the length of the commutator plate 8, so as to facilitate the removal of the slide bar 6 from the hole where the commutator plate is located. In this embodiment, the slide bar 6 is divided into three parts, from left to right: left slide bar 61, middle slide bar 62, and right slide bar 63, and the length of each part is less than the length of the commutator plate 8. A slide rail 13 is installed at the bottom of the second chamber 102. The slide rail 13 supports the middle slide bar 6 and assists the middle slide bar 6 in pressing the valve 7 upward against the commutator plate 8, ensuring a tight seal between the valve 7 and the commutator plate 8. The slide rail 13 is made of ceramic, POM (polyoxymethylene), or other materials with good lubricity and wear resistance, and is not easily damaged.

[0026] In this embodiment, the reversing plate 8 is provided with a first working hole 104, an exhaust hole 105, and a second working hole 106 in sequence. The first chamber 101 is provided with a first connecting hole 107, which is connected to the first working hole 104; the third chamber 103 is provided with a second connecting hole 108, which is connected to the second working hole 106; the exhaust hole 105 on the reversing plate 8 is connected to the main exhaust hole of the diaphragm pump.

[0027] The first chamber 101 is located on the left side of the slide rod 6, and this chamber is connected to the first working hole 104 on the reversing plate 8 through the first connecting hole 107; the second chamber 102 is connected to a compressed air source and is filled with compressed air; the third chamber 103 is located on the right side of the slide rod 6, and this chamber is connected to the second working hole 106 on the reversing plate through the second connecting hole 108. When the slide rod 6 moves to a certain position under the push of the diaphragm, compressed air enters one of the first chamber 101 and the third chamber 103 located on the left and right sides of the slide rod, while compressed air is discharged from the other, and a pressure difference is quickly formed on the left and right sides of the slide rod 6. This pressure difference pushes the slide rod to quickly change direction.

[0028] In this embodiment, the second working hole 106 (or the first working hole 104) on the reversing plate 8 is also connected to the control chamber of the air main valve 209 of the diaphragm pump. As the pilot reversing valve reverses, the second working hole 106 (or the first working hole 104) alternately fills and discharges compressed air into the control chamber of the air main valve 209, that is, it sends a reversing signal to the air main valve to drive the air main valve to reverse.

[0029] In this embodiment, the valve disc 7 and the reversing plate 8 are made of ceramic material. Driven by the slide rod 6, the valve disc 7 slides back and forth on the reversing plate 8. The valve disc 7 and the reversing plate 8 always keep in contact, and the two form a planar sliding and sealing, which solves the shortcomings of most current diaphragm pump pilot reversing valves, such as unreliable sealing, easy wear and scratching of the sealing ring, poor dirt resistance, and the need to add lubricant regularly, and greatly improves the sealing performance and service life.

[0030] In this embodiment, the slide bar 6 is provided with a first Y-ring 11 and a second Y-ring 12; the valve disc 7 is provided with a concave hole 109.

[0031] The pilot-operated directional valve described in this embodiment divides the slide rod into two or more pieces from left to right, and the length of each piece is less than or equal to the length of the directional plate. The slide rod can be removed from the hole where the directional plate is located. Since the Y-shaped sealing ring on the slide rod, as well as the sealing rings on the left and right contact rods, are all vulnerable parts, when the above-mentioned seals, slide rods, contact rods, and other components in the pilot-operated directional valve are damaged, it is only necessary to remove the air main valve and front cover, then remove the directional plate, remove the slide rod or contact rod from the directional plate, and then replace the damaged part. This process does not require removing the diaphragm pump from the infusion line, nor does it require completely disassembling the diaphragm pump from the outside to the inside, greatly simplifying the disassembly and assembly process during maintenance and greatly improving maintenance efficiency.

[0032] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments for application in other fields. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present utility model without departing from the technical solution of the present utility model shall still fall within the protection scope of the present invention.

Claims

1. A pilot directional control valve for a pneumatic double diaphragm pump that facilitates maintenance, characterized by: The valve body, the left end cover and the right end cover installed on the left and right ends of the valve body, the first sliding sleeve and the second sliding sleeve installed in the valve body, the sliding rod which can slide back and forth in the first sliding sleeve and the second sliding sleeve, the valve disc installed on the sliding rod and sliding with the sliding rod, the reversing plate which forms a plane sliding dynamic seal with the valve disc, the left contact rod and the right contact rod arranged on the left end cover and the right end cover respectively, the first chamber surrounded by the left end cover, the inner hole of the first sliding sleeve and the left side of the sliding rod, the second chamber surrounded by the sliding rod, the first sliding sleeve, the second sliding sleeve, the valve body and the reversing plate, and the third chamber surrounded by the right side of the sliding rod, the inner hole of the second sliding sleeve and the right end cover. The sliding rod is divided into two or more parts along the length direction, and the length of each part is not greater than the length of the reversing plate.

2. The pilot direction valve for a pneumatic double diaphragm pump easy to maintain according to claim 1, characterized in that: The second chamber is provided with a slide rail for supporting the sliding rod.

3. The pilot direction valve for a pneumatic double diaphragm pump easy to repair according to claim 1, characterized in that: The sliding rod comprises a left sliding rod, a middle sliding rod and a right sliding rod.

4. The pilot direction valve for a pneumatic double diaphragm pump easy to repair according to claim 1, characterized in that: The reversing plate is sequentially provided with a first working hole, an exhaust hole and a second working hole, the first chamber is provided with a first communication hole in communication with the first working hole, the third chamber is provided with a second communication hole in communication with the second working hole, and the exhaust hole of the reversing plate is in communication with the total exhaust hole of the diaphragm pump.

5. The pilot direction valve for a pneumatic double diaphragm pump easy to repair according to claim 4, characterized in that: The first chamber is located on the left side of the sliding rod, the chamber is in communication with the first working hole of the reversing plate through the first communication hole, the second chamber is in communication with the compressed air source, and the second chamber is filled with compressed air, the third chamber is located on the right side of the sliding rod, the chamber is in communication with the second working hole of the reversing plate through the second communication hole, when the sliding rod moves to a certain position under the pushing of the diaphragm, one of the first chamber and the third chamber located on the left and right sides of the sliding rod respectively enters compressed air, and the other discharges compressed air, a pressure difference is rapidly formed on the left and right sides of the sliding rod, and the pressure difference pushes the sliding rod to rapidly reverse.

6. The pilot direction valve for a pneumatic double diaphragm pump easy to repair according to claim 5, characterized in that: The second working hole or the first working hole of the reversing plate is also in communication with the control cavity of the air main valve of the diaphragm pump, with the reversing of the pilot reversing valve, the second working hole or the first working hole alternately charges and discharges compressed air to the control cavity of the air main valve, that is, sends a reversing signal to the air main valve, and drives the air main valve to reverse.

7. The pilot direction valve for a pneumatic double diaphragm pump easy to repair according to claim 6, characterized in that: The valve disc and the reversing plate are made of ceramic material, the valve disc reciprocally slides on the reversing plate under the driving of the sliding rod, and plane sliding dynamic seal is formed between the valve disc and the reversing plate.

8. The pilot direction valve for a pneumatic double diaphragm pump easy to repair according to claim 7, characterized in that: The sliding rod is provided with a first Y-shaped ring and a second Y-shaped ring, and the valve disc is provided with a recess hole.

9. The pilot direction valve for a pneumatic double diaphragm pump easy to repair according to claim 2, characterized in that: The slide rail is made of ceramic or POM material.

Images