Flow-adjustable manual diaphragm valve

Abstract

The invention discloses a flow-adjustable manual diaphragm valve, and relates to the technical field of valves. The flow-adjustable manual diaphragm valve comprises a valve body, a flow path, a diaphragm, a valve rod, a driving seat, an adjusting groove, an adjusting seat and an adjusting cavity, the valve rod is arranged in the adjusting cavity in a penetrating mode in the axial direction of the valve rod, a positioning part is arranged at the end, away from the diaphragm, of the valve rod, and positioning walls used for abutting against the positioning part are arranged at the two opposite ends of the adjusting cavity correspondingly. The two positioning walls are arranged in the axial direction of the valve rod. According to the manual diaphragm valve, the moving stroke of the valve rod can be adjusted by positioning the positioning part through the two positioning walls, so that the opening height and the closing height of the diaphragm can be adjusted, and then accurate flow adjustment of the manual diaphragm valve is achieved; meanwhile, the two positioning walls can position the valve rod, so that the adjusted flow is kept constant.

Description

Technical Field

[0001] The present application relates to the field of valve technology, and in particular to a flow-adjustable manual diaphragm valve. Background Art

[0002] Manual diaphragm valve is a diaphragm valve driven by a hand wheel, which is frequently used in food, medicine and other industries.

[0003] However, the existing manual diaphragm valve can only be kept in a fully open or fully closed state when in use, and cannot adjust the flow rate according to the specific pipeline working conditions, which greatly limits the application of manual diaphragm valves in some special pipeline working conditions; at the same time, the manual diaphragm valve may encounter unexpected situations such as vibration, impact, and misoperation during use, resulting in abnormal changes in the valve opening, which greatly affects the normal operation of the pipeline working conditions. Summary of the invention

[0004] In order to overcome the deficiencies of the prior art, the present application provides a manual diaphragm valve with adjustable flow.

[0005] The manual diaphragm valve provided in this application adopts the following technical solution: A flow-adjustable manual diaphragm valve comprises a valve body, a flow path opened in the valve body, a diaphragm arranged in the valve body for opening and closing the flow path, a valve stem movably arranged in a direction close to or away from the diaphragm for pressing the diaphragm, and a driving seat arranged on the valve body for driving the valve stem to move. The manual diaphragm valve also comprises an adjusting groove opened in the driving seat, an adjusting seat movably arranged in the adjusting groove along the axial direction of the valve stem, and an adjusting cavity opened in the adjusting seat. The valve stem is axially penetrated in the adjusting cavity, and a positioning portion is provided at one end of the valve stem away from the diaphragm. The opposite ends of the adjusting cavity respectively have positioning walls for resisting the positioning portion. The two positioning walls are arranged along the axial direction of the valve stem.

[0006] By adopting the above technical solution, the operator can change the position of the adjustment seat as needed, so as to adjust the movement stroke of the valve stem by positioning the positioning part through the two positioning walls, so as to adjust the opening height and closing height of the diaphragm, thereby realizing precise flow regulation of the manual diaphragm valve; at the same time, the two positioning walls can position the valve stem so that the adjusted flow rate remains constant.

[0007] Preferably, buffer sleeves are respectively provided on both sides of the positioning portion, and the buffer sleeves are retractable along their axial direction. Buffer grooves corresponding to the two buffer sleeves are respectively opened on the two positioning walls, and the projections of the two buffer sleeves on the two positioning walls coincide with the two buffer grooves.

[0008] By adopting the above technical solution, buffering can be achieved between the positioning part and the two positioning walls through the telescopic cooperation between the buffer sleeve and the buffer groove, thereby preventing the positioning part from directly hitting the positioning wall and affecting the movement of the valve stem.

[0009] Preferably, the diameter of each of the buffer sleeves gradually increases along the direction from the positioning portion to the corresponding buffer groove.

[0010] By adopting the above technical solution, the telescopic stability of the buffer sleeve is effectively improved, and the deflection of the buffer sleeve during the telescopic process is avoided.

[0011] Preferably, the adjustment seat includes a first seat body disposed in the adjustment groove and movable along the axial direction of the valve stem, a seat groove opened on the first seat body, and a second seat body disposed movably in the seat groove, the moving direction of the second seat body is the same as the moving direction of the first seat body, and the adjustment cavity is formed between the first seat body and the second seat body.

[0012] By adopting the above technical solution, the distance between the two positioning walls can be adjusted by the relative movement of the first seat body and the second seat body, which not only effectively increases the stroke adjustment range of the valve stem, but also enables the operator to independently adjust the opening height and closing height of the manual diaphragm valve to adapt to more pipeline working conditions.

[0013] Preferably, the driving seat has a rotating part rotatably connected to the valve body, the extension direction of the rotation axis of the rotating part is the same as the axial direction of the valve stem, a plurality of limit grooves are spaced apart on the outer peripheral side of the rotating part, a retractable limit rod is provided on the valve body, the retractable direction of the limit rod is perpendicular to the extension direction of the rotation axis of the rotating part, and the limit rod can be selectively inserted into one of the plurality of limit grooves.

[0014] By adopting the above technical solution, the rotating part can be maintained at the corresponding rotation position with the cooperation of the limit rod and the limit groove, avoiding abnormal rotation of the rotating part due to vibration, impact, misoperation, etc., thereby avoiding the influence of abnormal movement of the valve stem on the opening of the valve.

[0015] Preferably, a limit seat is provided on the valve body, the limit rod is slidably arranged in the limit seat along its axial direction, the limit seat is provided with a first elastic member, the end of the limit rod away from the rotating part is arranged in the first elastic member and is connected to the first elastic member, the limit seat is also provided with an unlocking module for driving the limit rod away from the rotating part, the unlocking module includes an unlocking column movable in a direction perpendicular to the limit rod and arranged in the limit seat, the end of the unlocking column has a first inclined surface, the side of the limit rod is provided with a first matching groove, the groove bottom of the first matching groove has a second inclined surface, the first inclined surface conflicts with the second inclined surface, and the first inclined surface and the second inclined surface are respectively inclined along the direction from the unlocking column to the limit rod toward the direction close to the rotating part.

[0016] By adopting the above technical solution, the limit rod can be tightly inserted in the limit groove under the action of the first elastic member, which effectively improves the insertion strength of the limit rod in the limit groove; at the same time, the operator can conveniently release the lock of the limit rod on the rotating part through the cooperation of the unlocking column and the first matching groove, which is convenient for the operator to normally adjust the opening of the diaphragm.

[0017] Preferably, a guide ring is connected to the groove opening of the limiting groove, and the guide ring includes a plurality of guide parts arranged circumferentially around the limiting groove, each of the guide parts has an arc-shaped guide surface, and a yield groove is formed between every two adjacent guide parts.

[0018] By adopting the above-mentioned technical scheme, the arc-shaped guide surface and the give way groove can reduce the insertion resistance of the limit rod and the difficulty of inserting the limit rod in the limit groove, so that the first elastic member can smoothly drive the limit rod to be inserted into the limit groove; at the same time, multiple guide parts can support the limit rod from the peripheral side of the limit rod to avoid relative shaking between the limit rod and the rotating part.

[0019] Preferably, retractable limit blocks are respectively arranged on the groove walls on both sides opposite to each other in the limit groove, a limit head is arranged on the end of the limit rod, the two limit blocks are respectively pressed against the two sides of the limit rod, and a limit cavity for accommodating the limit head is formed between the two limit blocks and the limit groove.

[0020] By adopting the above technical solution, when the limit rod is inserted into the limit groove, the two limit blocks can respectively clamp the limit rod and press against the rear end of the limit head, thereby effectively improving the insertion strength of the limit rod in the limit groove and preventing the limit rod from being separated from the limit groove and causing limit failure.

[0021] Preferably, the limit head is spherical, the two limit blocks are combined into a limit portion, and the limit portion is respectively provided with a second matching groove matching the limit head on one side facing the limit head and on the other side facing away from the limit head.

[0022] By adopting the above technical solution, the two limiting blocks can be separated smoothly under the cooperation of the spherical limiting head and the two second matching grooves, which facilitates the insertion of the limiting rod in the limiting groove.

[0023] Preferably, the two limit blocks are respectively provided with slots on their end surfaces close to each other, and the two slots are respectively engaged with the two side portions of the limit rod.

[0024] By adopting the above technical solution, the insertion strength of the limiting rod in the limiting groove is further improved.

[0025] In summary, the present invention includes at least one of the following beneficial technical effects: The operator can change the position of the adjustment seat as needed, and adjust the movement stroke of the valve stem by positioning the positioning part through the two positioning walls, so as to adjust the opening height and closing height of the diaphragm, thereby realizing precise flow regulation of the manual diaphragm valve; at the same time, the two positioning walls can position the valve stem to keep the adjusted flow constant. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 is a schematic diagram of the three-dimensional structure of the manual diaphragm valve in the embodiment of the present application; Figure 2 is a longitudinal cross-sectional schematic diagram of a manual diaphragm valve in an embodiment of the present application; Figure 3 yes Figure 2 A is an enlarged schematic diagram; Figure 4 yes Figure 2 The enlarged schematic diagram of point B in FIG.

[0027] Markings in the accompanying drawings: 1. Valve body; 2. Flow path; 3. Diaphragm; 4. Valve stem; 5. Drive seat; 5a. Rotating part; 5b. Hand wheel; 6. Adjusting groove; 7. Adjusting seat; 7a. First seat body; 7b. Second seat body; 8. Adjusting cavity; 8a. First positioning wall; 8b. Second positioning wall; 9. Positioning part; 10. Buffer sleeve; 11. Buffer groove; 12. Limiting groove; 13. Limiting rod; 13a. Limiting head; 14. Limiting seat; 15. First elastic member; 16. Unlocking module; 16a. Unlocking column; 16b. First inclined surface; 17. First matching groove; 17a. Second inclined surface; 18. Guide ring; 18a. Guide part; 18b. Make way groove; 19. Limiting block; 20. Limiting cavity; 21. Second matching groove; 22. Slot; 23. Slot cover; 24. Mounting groove; 25. Second elastic member. DETAILED DESCRIPTION

[0028] The following is combined with Figure 1-4 The present invention is described in further detail.

[0029] In the description of the present invention, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., and orientations or positional relationships indicated are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0030] See also Figure 1-4 As shown, a flow-adjustable manual diaphragm valve is shown, which includes a valve body 1, a flow path 2 opened in the valve body 1, a deformable diaphragm 3 arranged in the valve body 1 for opening and closing the flow path 2, a valve stem 4 for pressing the diaphragm 3 and movable in a direction close to or away from the diaphragm 3, and a drive seat 5 arranged on the valve body 1 for driving the valve stem 4 to move. The diaphragm 3 can be deformed in the up and down directions, the valve stem 4 extends in the vertical direction and its lower end is connected to the diaphragm 3, the drive seat 5 is rotatably connected to the upper end of the valve body 1, and the valve stem 4 is inserted in the drive seat 5 and is threadedly connected to the drive seat 5. By rotating the drive seat 5, the valve stem 4 can move in the vertical direction under the threaded cooperation of the drive seat 5 and drive the diaphragm 3 to open and close.

[0031] In this embodiment, combined with Figure 2 As shown, the manual diaphragm valve also includes an adjustment groove 6 opened on the driving seat 5, an adjustment seat 7 movably arranged in the adjustment groove 6 along the vertical direction, and an adjustment cavity 8 opened in the adjustment seat 7. The valve stem 4 is axially inserted into the adjustment cavity 8. The end of the valve stem 4 away from the diaphragm 3 has a positioning portion 9. The positioning portion 9 is annular and sleeved on the valve stem 4. The upper and lower ends of the adjustment cavity 8 respectively have positioning walls for resisting the positioning portion 9.

[0032] The adjusting seat 7 is threadedly connected to the groove wall of the adjusting groove 6. When the operator rotates the adjusting seat 7, the adjusting seat 7 can move in the vertical direction under the cooperation of the thread of the adjusting groove 6, and the positioning walls at the upper and lower ends of the adjusting cavity 8 can also move with the adjusting seat 7. In this way, the interference position between the positioning part 9 on the valve stem 4 and the two positioning walls will also change accordingly. In other words, the moving stroke of the valve stem 4 can change with the movement of the adjusting seat 7, and the valve stem 4 can stop at different positions during its movement. The valve stem 4 stopped at different positions can make the diaphragm 3 have different opening heights and closing heights, thereby realizing accurate flow regulation of the manual diaphragm valve; at the same time, the two positioning walls can position the valve stem 4 so that the adjusted flow remains constant; and the blocking of the valve stem 4 by the two positioning walls can prevent the valve stem 4 from excessive movement, thereby preventing the diaphragm 3 from being overstretched, and extending the service life of the diaphragm 3.

[0033] Among them, the positioning wall at the upper end of the regulating chamber 8 is the first positioning wall 8a, and the positioning wall at the lower end is the second positioning wall 8b. The valve stem 4 gradually drives the diaphragm 3 to open the flow path 2 during the upward movement, and the flow in the flow path 2 gradually increases. When the positioning portion 9 conflicts with the first positioning wall 8a, the diaphragm 3 is at the maximum opening height, and the flow in the flow path 2 is the largest at this time; the valve stem 4 gradually drives the diaphragm 3 to close the flow path 2 during the downward movement, and the flow in the flow path 2 gradually decreases. When the positioning portion 9 conflicts with the second positioning wall 8b, the diaphragm 3 is at the minimum closing height, and the flow path 2 is completely closed at this time. By adjusting the position of the regulating seat 7, the maximum opening height and the minimum closing height of the diaphragm 3 can be changed, so as to accurately adjust the flow in the flow path 2 and keep the adjusted flow constant.

[0034] In this embodiment, combined with Figure 2 and Figure 3 As shown, buffer sleeves 10 extending in the vertical direction are respectively arranged on both sides of the positioning portion 9, and the buffer sleeves 10 are bellows and are retractable along their axial direction. Buffer grooves 11 corresponding to and matching the two buffer sleeves 10 are respectively opened on the two positioning walls, and the projections of the two buffer sleeves 10 on the two positioning walls coincide with the two buffer grooves 11. The diameter of each buffer sleeve 10 gradually increases along the direction from the positioning portion 9 to the corresponding buffer groove 11.

[0035] When the positioning portion 9 approaches the positioning wall, the buffer sleeve 10 pre-contacts the positioning wall and is inserted into the buffer groove 11. The buffer sleeve 10 gradually shrinks in the buffer groove 11 and relieves the impact force of the positioning portion 9, thereby achieving buffering between the positioning portion 9 and the positioning wall, avoiding the positioning portion 9 from directly hitting the positioning wall and affecting the movement of the valve stem 4.

[0036] In this embodiment, combined again Figure 2As shown, the adjustment seat 7 includes a first seat body 7a disposed in the adjustment groove 6 and movable along the vertical direction, a seat groove formed on the first seat body 7a, and a second seat body 7b disposed in the seat groove and movable, a first positioning wall 8a is located at the bottom of the second seat body 7b, a second positioning wall 8b is located at the bottom of the first seat body 7a, the moving direction of the second seat body 7b is the same as that of the first seat body 7a, and an adjustment cavity 8 is formed between the first seat body 7a and the second seat body 7b. The first seat body 7a is threadedly connected to the groove wall of the adjustment groove 6, and the second seat body 7b is threadedly connected to the groove wall of the seat groove.

[0037] When adjusting the adjustment seat 7, the first seat body 7a and the second seat body 7b can be screwed separately as needed. Screwing the first seat body 7a can realize the movement of the second positioning wall 8b, so that the valve stem 4 can stop at different positions when descending to adjust the closing height of the diaphragm 3; screwing the second seat body 7b can realize the movement of the first positioning wall 8a, so that the valve stem 4 can stop at different positions when ascending to adjust the opening height of the diaphragm 3. In this way, the first positioning wall 8a and the second positioning wall 8b can be adjusted separately as needed, which can not only effectively increase the stroke adjustment range of the valve stem 4, but also can independently adjust the opening height and closing height of the manual diaphragm valve to adapt to more pipeline working conditions.

[0038] The slot opening of the adjustment slot 6 is also provided with a slot cover 23 , and the slot cover 23 is detachably connected to the adjustment seat 7 via a buckle, and the slot cover 23 has an inner cavity for accommodating the first seat body 7a and the second seat body 7b.

[0039] In this embodiment, the driving seat 5 includes a rotating portion 5a located inside the valve body 1 and rotatably connected to the valve body 1, a hand wheel 5b located outside the valve body 1 and coaxially connected to the rotating portion 5a, the rotating portion 5a is threadedly connected to the valve stem 4, and the adjusting groove 6 is coaxially opened in the hand wheel 5b. The extension direction of the rotation axis of the rotating portion 5a is the same as the axial direction of the valve stem 4, and a plurality of limiting grooves 12 are spaced apart on the outer peripheral side of the rotating portion 5a. A retractable limiting rod 13 is provided on the valve body 1, and the retracting direction of the limiting rod 13 is perpendicular to the extension direction of the rotation axis of the rotating portion 5a. The limiting rod 13 can be selectively inserted into one of the plurality of limiting grooves 12.

[0040] When adjusting the flow path 2, turn the hand wheel 5b, and the valve stem 4 moves up and down with the cooperation of the thread of the rotating part 5a to adjust the opening of the diaphragm 3. After the adjustment, insert the limit rod 13 into the limit groove 12. The rotating part 5a can be maintained in the corresponding rotation position with the cooperation of the limit rod 13 and the limit groove 12, avoiding abnormal rotation of the rotating part 5a due to vibration, impact, misoperation, etc., thereby avoiding the influence of abnormal movement of the valve stem 4 on the opening of the valve.

[0041] In this embodiment, combined with Figure 2 and Figure 4 As shown, a limit seat 14 is provided on one side of the valve body 1 in the horizontal direction, and the limit rod 13 is slidably arranged in the limit seat 14 along the horizontal direction. A first elastic member 15 is provided on the limit seat 14, and the first elastic member 15 is a spring. One end of the limit rod 13 away from the rotating part 5a is arranged in the first elastic member 15 and connected to the first elastic member 15. The limit seat 14 is also provided with an unlocking module 16 for driving the limit rod 13 away from the rotating part 5a. The unlocking module 16 includes an unlocking column 16a movably arranged in the limit seat 14 along the vertical direction, and the end of the unlocking column 16a has a first inclined surface 16b. A first matching groove 17 is provided on the side of the limit rod 13, and the bottom of the first matching groove 17 has a second inclined surface 17a. The first inclined surface 16b conflicts with the second inclined surface 17a, and the first inclined surface 16b and the second inclined surface 17a are respectively inclined along the vertical direction toward the direction close to the rotating part 5a.

[0042] After the limit rod 13 is inserted into the limit groove 12, it can be tightly positioned in the limit groove 12 under the action of the first elastic member 15, which effectively improves the insertion strength of the limit rod 13 in the limit groove 12; when the opening of the diaphragm 3 needs to be operated, it is only necessary to press the unlocking column 16a, and the first inclined surface 16b gradually squeezes the second inclined surface 17a during the descending process of the unlocking column 16a. During the squeezing process, the limit rod 13 moves in the direction away from the rotating part 5a and gradually disengages from the limit groove 12, so as to release the lock of the limit rod 13 on the rotating part 5a. After the lock is released, the operator can conveniently adjust the opening of the diaphragm 3 normally.

[0043] In this embodiment, the slot of the limiting slot 12 is connected with a guide ring 18, and the guide ring 18 includes a plurality of guide portions 18a arranged around the circumference of the limiting slot 12, each guide portion 18a has an arc-shaped guide surface, and a clearance groove 18b is formed between each two adjacent guide portions 18a. The arc-shaped guide surface and the clearance groove 18b can reduce the insertion resistance of the limiting rod 13, reduce the difficulty of the limiting rod 13 in the limiting slot 12, so that the first elastic member 15 can smoothly drive the limiting rod 13 to be inserted into the limiting slot 12; at the same time, the plurality of guide portions 18a can resist the limiting rod 13 from the circumferential side of the limiting rod 13, and avoid relative shaking between the limiting rod 13 and the rotating portion 5a.

[0044] Mounting grooves 24 are respectively provided on the upper and lower groove walls opposite to each other of the limiting groove 12, and a second elastic member 25 and a limiting block 19 are provided in the mounting groove 24. The second elastic member 25 is a spring, and the limiting block 19 is connected to the second elastic member 25 and can be extended and retracted under the action of the second elastic member 25. A limiting head 13a is provided at the end of the limiting rod 13, and two limiting blocks 19 are respectively pressed against the two sides of the limiting rod 13, and a limiting cavity 20 for accommodating the limiting head 13a is formed between the two limiting blocks 19 and the limiting groove 12. When the limiting rod 13 is inserted into the limiting groove 12, the two limiting blocks 19 can respectively clamp the limiting rod 13 and abut against the rear end of the limiting head 13a, which effectively improves the insertion strength of the limiting rod 13 in the limiting groove 12 and prevents the limiting rod 13 from being separated from the limiting groove 12 and causing the limiting failure.

[0045] The limiting head 13a is spherical, and two limiting blocks 19 are combined into a limiting portion, and the limiting portion is provided with a second matching groove 21 matching the limiting head 13a on one side facing the limiting head 13a and the other side facing away from the limiting head 13a. The two limiting blocks 19 can be separated smoothly under the cooperation of the spherical limiting head 13a and the two second matching grooves 21, so as to facilitate the insertion of the limiting rod 13 in the limiting groove 12.

[0046] In this embodiment, a slot 22 is provided on one end surface of the two limit blocks 19 close to each other. The slot 22 matches the side profile of the limit rod 13 , and the two slots 22 are respectively engaged with the two sides of the limit rod 13 .

[0047] The embodiments of this specific implementation method are all preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention. Therefore, any equivalent changes made based on the structure, shape, and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A flow-adjustable manual diaphragm valve, comprising a valve body (1), a flow path (2) provided in the valve body (1), a diaphragm (3) provided in the valve body (1) for opening and closing the flow path (2), a valve stem (4) movably arranged in a direction approaching or moving away from the diaphragm (3) for pressing the diaphragm (3), and a drive seat (5) provided on the valve body (1) for driving the valve stem (4) to move, characterized in that: The manual diaphragm valve also includes an adjustment groove (6) provided on the driving seat (5), an adjustment seat (7) arranged in the adjustment groove (6) and movable along the axial direction of the valve stem (4), and an adjustment cavity (8) provided in the adjustment seat (7); the valve stem (4) is inserted into the adjustment cavity (8) along its axial direction; the end of the valve stem (4) away from the diaphragm (3) has a positioning portion (9); the two opposite ends of the adjustment cavity (8) respectively have positioning walls for resisting the positioning portion (9); the two positioning walls are arranged along the axial direction of the valve stem (4).

2. A flow-adjustable manual diaphragm valve according to claim 1, characterized in that: Buffer sleeves (10) are respectively arranged on both sides of the positioning portion (9), and the buffer sleeves (10) are telescopically arranged along their axial direction. Buffer grooves (11) corresponding to and matching the two buffer sleeves (10) are respectively opened on the two positioning walls, and the projections of the two buffer sleeves (10) on the two positioning walls respectively overlap with the two buffer grooves (11).

3. A flow-adjustable manual diaphragm valve according to claim 2, characterized in that: The diameter of each buffer sleeve (10) gradually increases along the direction from the positioning portion (9) to the corresponding buffer groove (11).

4. The flow-adjustable manual diaphragm valve according to claim 1, characterized in that: The adjustment seat (7) comprises a first seat body (7a) which is movable along the axial direction of the valve stem (4) and is arranged in the adjustment groove (6), a seat groove opened on the first seat body (7a), and a second seat body (7b) which is movably arranged in the seat groove, wherein the moving direction of the second seat body (7b) is the same as the moving direction of the first seat body (7a), and the adjustment cavity (8) is formed between the first seat body (7a) and the second seat body (7b).

5. The flow-adjustable manual diaphragm valve according to claim 1, characterized in that: The driving seat (5) has a rotating part (5a) rotatably connected to the valve body (1), the extension direction of the rotation axis of the rotating part (5a) is the same as the axial direction of the valve stem (4), and a plurality of limit grooves (12) are spaced apart on the outer peripheral side of the rotating part (5a). A retractable limit rod (13) is provided on the valve body (1), and the retracting direction of the limit rod (13) is perpendicular to the extension direction of the rotation axis of the rotating part (5a), and the limit rod (13) can be selectively inserted into one of the plurality of limit grooves (12).

6. A flow-adjustable manual diaphragm valve according to claim 5, characterized in that: The valve body (1) is provided with a limit seat (14), the limit rod (13) is slidably inserted into the limit seat (14) along its axial direction, the limit seat (14) is provided with a first elastic member (15), one end of the limit rod (13) away from the rotating part (5a) is inserted into the first elastic member (15) and connected to the first elastic member (15), and the limit seat (14) is also provided with an unlocking module (16) for driving the limit rod (13) away from the rotating part (5a), and the unlocking module (16) includes a spring along a direction perpendicular to the limit rod (13) and a spring for locking the limit rod (13). An unlocking column (16a) is movably arranged in the direction of the unlocking column (16a) and is penetrated in the limiting seat (14), the end of the unlocking column (16a) has a first inclined surface (16b), the side of the limiting rod (13) is provided with a first matching groove (17), the groove bottom of the first matching groove (17) has a second inclined surface (17a), the first inclined surface (16b) is in conflict with the second inclined surface (17a), and the first inclined surface (16b) and the second inclined surface (17a) are respectively inclined along the direction from the unlocking column (16a) to the limiting rod (13) towards the direction close to the rotating part (5a).

7. The flow-adjustable manual diaphragm valve according to claim 5, characterized in that: A guide ring (18) is connected to the groove opening of the limiting groove (12), and the guide ring (18) includes a plurality of guide portions (18a) arranged circumferentially around the limiting groove (12), each of the guide portions (18a) having an arc-shaped guide surface, and a clearance groove (18b) is formed between each two adjacent guide portions (18a).

8. The flow-adjustable manual diaphragm valve according to claim 5, characterized in that: Retractable limit blocks (19) are respectively arranged on the groove walls on both sides opposite to each other of the limit groove (12); a limit head (13a) is arranged at the end of the limit rod (13); the two limit blocks (19) are respectively pressed against the two sides of the limit rod (13); and a limit cavity (20) for accommodating the limit head (13a) is formed between the two limit blocks (19) and the limit groove (12).

9. A flow-adjustable manual diaphragm valve according to claim 8, characterized in that: The limiting head (13a) is spherical, and the two limiting blocks (19) are combined into a limiting portion, and a side portion of the limiting portion facing the limiting head (13a) and a side portion facing away from the limiting head (13a) are respectively provided with a second matching groove (21) matching the limiting head (13a).

10. The flow-adjustable manual diaphragm valve according to claim 8, characterized in that: A clamping groove (22) is respectively arranged on one end surface of the two limit blocks (19) close to each other, and the two clamping grooves (22) are respectively engaged with two side portions of the limit rod (13).

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