Push rod and valve rod connecting device of pneumatic diaphragm type straight stroke regulating valve

Abstract

The utility model discloses a pneumatic diaphragm type straight stroke regulating valve push rod and valve rod connecting device which comprises a push rod and a valve rod, the push rod is connected with a first connecting block, and the valve rod is connected with a second connecting block. A pair of side plates are arranged on the two sides of the first connecting block and the second connecting block, and the side plates are symmetrically arranged along the center; the side plate is composed of at least two stainless steel plates, the first connecting block is fixedly connected with the side plate, and the second connecting block is fixedly connected with the side plate. The utility model provides a connecting device for a push rod and a valve rod, which is adjustable, easy to replace and simple to manufacture, and aims to overcome the defect that time and labor are wasted in replacement after a connecting block wire of the push rod and the valve rod of the existing pneumatic diaphragm type straight stroke regulating valve is seriously abraded.

Description

Technical Field

[0001] The utility model relates to the technical field of pneumatic diaphragm direct stroke control valves, and particularly relates to a connecting device between a push rod and a valve rod of a pneumatic diaphragm direct stroke control valve. Background Technique

[0002] A control valve usually consists of a pneumatic actuator and a valve body. The direct stroke mainly has two types: direct through single-seat type and direct through double-seat type. The latter has the characteristics of large flow capacity, small unbalanced force and stable operation. The actuator is the driving device of the control valve, which generates a corresponding thrust according to the magnitude of the signal pressure, so that the push rod generates a corresponding displacement, thereby driving the valve core of the control valve to act. The pneumatic diaphragm actuator has the characteristics of simple structure, reliable action, convenient maintenance and low price, and is the most widely used actuator, usually especially suitable for occasions with large flow rate, high pressure drop and less leakage.

[0003] However, when used to regulate the steam pipeline flow rate, due to the long-term use of the pneumatic diaphragm direct stroke control valve for steam flow regulation, there is a problem that the thread of the connecting block between the push rod and the valve rod is severely worn. If the push rod and the valve rod cannot be effectively connected, the pneumatic diaphragm direct stroke control valve cannot effectively control the steam flow rate.

[0004] The existing technology can only cut the steam into the bypass operation, close the stop valve of the main steam line, cut out the control valve and no longer use it, remove the connecting block between the push rod and the valve rod, and send it to a processing factory with a CNC lathe for overall reprocessing according to the old dimensions. However, because the required quantity is small, it is not convenient for rapid processing, time-consuming and costly, increasing the production cost. Moreover, using the bypass to transport steam for heating the medium in the heat exchanger cannot regulate the steam consumption. Reprocessing the connecting block takes too long, resulting in unqualified products, which is not conducive to the company's safe production and low work efficiency. Content of the Utility Model

[0005] The technical problem to be solved by the utility model is to provide a connecting device between a push rod and a valve rod that is adjustable, easy to replace and simple to manufacture, aiming at the disadvantages of time-consuming and laborious replacement of the severely worn thread of the connecting block between the push rod and the valve rod of the existing pneumatic diaphragm direct stroke control valve.

[0006] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0007] A connecting device between a push rod and a valve rod of a pneumatic diaphragm direct stroke control valve, including a push rod and a valve rod, characterized in that a first connecting block is connected to the push rod, and a second connecting block is connected to the valve rod; a pair of side plates are arranged on both sides of the first connecting block and the second connecting block, and the side plates are symmetrically arranged along the center; the side plates are composed of at least two stainless steel plates, wherein the first connecting block is fixedly connected to the side plates, and the second connecting block is fixedly connected to the side plates.

[0008] Further, the side plate is composed of three stainless steel plates from top to bottom, and the three stainless steel plates are arranged in a stepped manner. The overlapping part between adjacent two stainless steel plates is connected by bolts and nuts. The advantage of the stepped arrangement of the steel plates is that when the diameters of the push rod and the valve rod differ greatly, the distance can be gradually reduced.

[0009] Further, a vertically arranged oblong screw hole is provided at the connection between the stainless steel plates, and at least two of the waist-shaped holes are provided; bolts and nuts are provided in the waist-shaped holes. By providing the waist-shaped holes, the fixing position of the nut can be adjusted according to the distance between the two connecting blocks.

[0010] Further, the inner side of the first connecting block is machined with threads, and the inner side of the second connecting block is machined with threads.

[0011] Further, threads are provided on the push rod, and the first connecting block is threadedly connected to the push rod. Threads are provided on the valve rod, and the second connecting block is threadedly connected to the valve rod. Threadedly connecting the connecting blocks to the push rod and the valve rod makes the whole connecting device easier to disassemble and replace.

[0012] The beneficial effects of the present utility model are as follows: The device is simple to manufacture, low in cost and strong in applicability. Compared with the original connecting block, the device does not need to use complex processing methods and can be made with only simple parts; by providing the waist-shaped holes, the device can adjust the length between the push rod and the valve rod, and there is no need to frequently replace the worn connecting blocks, which greatly saves the production cost and time cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 is a schematic structural diagram of the present utility model;

[0014] Figure 2 is a schematic structural diagram of Embodiment 2 of the present utility model;

[0015] Figure 3 is a schematic diagram of the connection of the stainless steel plates;

[0016] In the figure, 1 - membrane chamber, 2 - valve seat, 3 - push rod, 4 - first connecting block, 5 - valve rod, 6 - second connecting block, 7 - side plate. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0017] The technical solution of the present utility model will be further described below with reference to the accompanying drawings.

[0018] As Figure 1As shown in the figure, a connecting device for a push rod 3 and a valve stem 5 of a pneumatic diaphragm type direct stroke regulating valve. The device itself, including the diaphragm chamber and the valve seat, are both prior arts and will not be elaborated here. It includes a first connecting block 4 connected to the push rod 3, and a second connecting block 6 is connected to the valve stem 5. Both the first connecting block 4 and the second connecting block 6 are bolts. The first connecting block 4 is threadedly connected to the push rod 3, and the second connecting block 6 is threadedly connected to the valve stem 5. A pair of side plates 7 are welded on both sides of the first connecting block 4 and the second connecting block 6. The side plates 7 are composed of at least two stainless steel plates. There are vertically arranged oval-shaped screw holes at the connection between the stainless steel plates. The overlapping part between adjacent two stainless steel plates is connected by bolts and nuts. By adjusting the position of the bolts in the oval holes, the length of the side plates 7 can be adjusted.

[0019] Embodiment 1

[0020] In this embodiment, there is a large difference in the diameters of the push rod 3 and the valve stem 5. The first connecting block 4 and the second connecting block 6 are threaded on the inner side. Threads are processed on the push rod 3 and the valve stem 5. The first connecting block 4 is threadedly connected to the push rod 3, and the second connecting block 6 is threadedly connected to the valve stem 5. The side plates 7 are symmetrically arranged along the center line on both sides of the first connecting block 4 and the second connecting block 6. They are composed of three stainless steel plates from top to bottom, and the three stainless steel plates are arranged in a stepped manner. The distance is gradually reduced by the method of gradient connection. The upper side plate 7 is welded to the first connecting block 4, and the lower side plate 7 is welded to the second connecting block 6. The upper and lower two side plates 7 are then connected to each other by the middle stainless steel plate. There are waist-shaped holes at the overlapping part of all stainless steel plates, and they are fixed by bolts and nuts. Such a setting allows the instrument and meter maintenance worker to adjust the distance between the push rod 3 and the valve stem 5 of the regulating valve according to different regulating valves, saving the time and labor costs for the instrument and meter maintenance worker to reinstall.

[0021] Embodiment 2

[0022] When the diameters of the push rod 3 and the valve stem 5 are similar, on the basis of Embodiment 1, the three stainless steel plates of the side plate 7 are changed to two stainless steel plates. The upper side plate 7 is welded to the first connecting block 4, and the lower side plate 7 is welded to the second connecting block 6. There are waist-shaped holes at the overlapping part between the two side plates 7, and they are fixed by bolts and nuts. It is not necessary to use three stainless steel plates to form the side plate 7 to achieve the gradually reduced distance connection between the push rod 3 and the valve stem 5.

[0023] When there are no threads processed on the push rod 3 and the valve stem 5, the first connecting block 4 can also be welded to the push rod 3, and the second connecting block 6 can be welded to the valve stem 5.

[0024] Due to the low cost of stainless steel nuts, the connecting device between the push rod 3 and the valve stem 5 of this pneumatic diaphragm direct stroke regulating valve can be mass-produced usually. During normal inspection, when signs of wear are found on the threads of the connecting block between the push rod 3 and the valve stem 5 of the pneumatic diaphragm direct stroke regulating valve, it can be directly replaced, greatly saving the production cost and the time cost of re-entering the factory for overall machining of the connecting block.

[0025] The beneficial effects of the present utility model are as follows: The device is simple to manufacture, low in cost, and strong in applicability. Compared with the original connecting block, the device does not require complex processing methods and can be made with only simple parts; by setting waist-shaped holes, the device can adjust the length between the push rod and the valve stem, eliminating the need to frequently replace the connecting block with worn threads, greatly saving the production cost and the time cost.

Claims

1. A connecting device for a push rod and a valve stem of a pneumatic diaphragm direct stroke regulating valve, comprising a push rod (3) and a valve stem (5), characterized in that, A first connecting block (4) is connected to the push rod (3), and a second connecting block (6) is connected to the valve stem (5); a pair of side plates (7) are provided on both sides of the first connecting block (4) and the second connecting block (6), and the side plates (7) are arranged symmetrically about the center; the side plates (7) are composed of at least two stainless steel plates, and the first connecting block (4) is fixedly connected to the side plates (7), and the second connecting block (6) is fixedly connected to the side plates (7).

2. The push rod and valve stem connection device of a pneumatic diaphragm direct stroke regulating valve according to claim 1, characterized in that, The side plates (7) are successively composed of three stainless steel plates from top to bottom, and the three stainless steel plates are arranged in a stepped manner, and the overlapping parts between adjacent two stainless steel plates are connected by bolts and nuts.

3. The connecting device between the push rod and the valve stem of a pneumatic diaphragm direct stroke regulating valve according to claim 1, characterized in that, Vertical kidney-shaped holes are provided at the joints between the stainless steel plates, and at least two kidney-shaped holes are provided.

4. A connecting device between a push rod and a valve stem of a pneumatic diaphragm direct stroke regulating valve according to claim 1, characterized in that Threads are machined on the inner side of the first connecting block (4), and threads are machined on the inner side of the second connecting block (6).

5. The connecting device between the push rod and the valve stem of a pneumatic diaphragm direct stroke regulating valve according to claim 4, characterized in that, Threads are provided on the push rod (3), and the first connecting block (4) is threadedly connected to the push rod (3), and threads are provided on the valve stem (5), and the second connecting block (6) is threadedly connected to the valve stem (5).

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