Shock Absorbing Structure of the Valve Stem of the Electromagnetic Hydraulic Control Directional Valve

Abstract

The shock-absorbing structure of the valve stem of an electromagnetic-hydraulic control reversing valve is provided on the valve stem body in the shape of a cylinder. The valve stem includes a limiting cylinder body, a support cylinder body, and a sliding cylinder body that are symmetrically arranged on the left and right. A buffer flow channel is arranged on the side surface of the sliding cylinder body along the axial direction; an indented oil storage groove is provided at the end of the buffer flow channel. Compared with the prior art, the oil storage groove provides a space for absorbing shock in the critical state during the switching process. During the critical pressure and flow conditions of the function switching and during the valve reversing process, the pipeline back pressure gradually decreases, ensuring small pipeline shock, smooth operation of the oil cylinder, and effectively and smoothly transitioning the conversion of the moment of inertia.

Description

Technical Field

[0001] The present invention relates to a spool of an electromagnetic-hydraulic control reversing valve communicating with a PTAB cavity, and more specifically to a shock-absorbing structure of a valve stem of an electromagnetic-hydraulic control reversing valve. Background Art

[0002] The opening and closing die circuit of an injection molding machine is controlled by an electro-hydraulic reversing valve. Refer to Figures 1 to 1b , in the prior art, the shape of the existing spool is a cylindrical part, with two left limit cylinders 1 and two right limit cylinders 2 with reduced diameters for limiting the stroke at both ends; further towards the center, there are two left support cylinders 3 and two right support cylinders 4 for supporting accessories; the middle main cylinder is the left sliding cylinder 5 and the right sliding cylinder 6 that fit the inner hole of the body. In the prior art, left and right symmetric V-shaped ramp grooves are respectively machined on the left sliding cylinder 5 and the right sliding cylinder 6. And the left and right ends of each sliding cylinder are asymmetrically designed, that is, three V-shaped ramp grooves are distributed on the left side of the left sliding cylinder 5, and two V-shaped ramp grooves are distributed on the right side. And the two middle cylinders 5 and 6 are symmetric about the left and right, and the said V-shaped ramp grooves are used as buffer flow channels.

[0003] Refer to Figure 6 , during the switching process of the function control of the pressure and flow rate of the system and the load, a very unstable turbulent flow phenomenon appears, and these energies are amplified under the area effect of the actuators (cylinders, motors, etc.), resulting in the inability to decrease the operating inertia of the equipment, and generating machine vibrations that affect the accuracy.

[0004] Due to reasons such as the short V-shaped ramp, small opening, and shallow depth of the existing valve stem, the back pressure of the pipeline is too high. When starting to reverse and when the reversing is in place, the electromagnetic reversing valve cannot effectively reduce the impact during reversing, which will cause impact on the pipeline or the cylinder, and the cylinder is prone to jitter or crawling phenomenon. Summary of the Invention

[0005] The present invention aims to provide a shock-absorbing structure of a valve stem of an electromagnetic-hydraulic control reversing valve to solve the existing problems.

[0006] To achieve the above object, the technical solution adopted by the present invention is provided on a valve stem body in the shape of a cylinder. The valve stem body includes limit cylinders, support cylinders, and sliding cylinders that are symmetrically arranged on the left and right. Buffer flow channels are arranged along the axial direction on the side surface of the sliding cylinder; an indented oil storage groove is provided at the end of the buffer flow channel.

[0007] Wherein, one end of the buffer flow channel is opened at the end of the side surface of the sliding cylinder, and the other end is arranged in the middle of the side surface of the sliding cylinder.

[0008] Wherein, the oil storage groove is a circular groove, that is, the notch on the side surface is circular.

[0009] Among them, the buffer flow channel is a V-shaped ramp groove, that is, the cross-section of the buffer flow channel is V-shaped.

[0010] Among them, the width of the V-shaped ramp groove shrinks from both ends of the sliding cylinder body towards the inner end, also in a V shape.

[0011] Among them, V-shaped ramp grooves are provided at both ends of the side surface of the sliding cylinder body, and the V-shaped ramp grooves facing each other at both ends are arranged staggeredly.

[0012] Among them, the length of the V-shaped ramp groove is greater than half of the axial length of the cylinder. Since the V-shaped ramp is relatively long, the back pressure of the pipeline is very small and the circular groove is increased. When the valve changes direction, the impact is very small and the oil cylinder operates smoothly.

[0013] Among them, four V-shaped ramp grooves are distributed at the left end of the sliding cylinder body, and circular grooves are provided at the tops of three of the V-shaped ramp grooves. Four V-shaped ramp grooves are distributed at the right end of the sliding cylinder body, and circular grooves are provided at the tops of two diagonal V-shaped ramp grooves.

[0014] Among them, the V-shaped ramp grooves and circular grooves on the two sliding cylinder bodies on the valve stem body are also symmetrically arranged left and right.

[0015] Compared with the prior art, the present invention utilizes the critical state of the oil storage tank during the switching process to provide a space for absorbing impact. During the critical pressure and flow conditions of the function switching and during the valve commutation process, the pipeline back pressure gradually decreases, ensuring small pipeline impact and smooth operation of the oil cylinder, and effectively and smoothly transitioning the conversion of the moment of inertia; under the same pressure and flow conditions, the flow velocity is relatively slow and stable, and the valve core is more stable when switching and resetting. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a schematic structural diagram of the existing valve stem;

[0017] Figure 1a is Figure 1 the cross-sectional view of the A-A plane in

[0018] Figure 1b is Figure 1 the cross-sectional view of the B-B plane in

[0019] Figure 2 is a schematic structural diagram of an embodiment of the present invention;

[0020] Figure 2a is Figure 2 the cross-sectional view of the A-A plane in

[0021] Figure 2b is Figure 2 the cross-sectional view of the B-B plane in

[0022] Figure 2c isFigure 2 Cross-sectional view of the C-C plane;

[0023] Figure 2d is Figure 2 Cross-sectional view of the D-D plane;

[0024] Figure 3 Instruction diagram of an embodiment of the present invention;

[0025] Figure 4 Instruction diagram of an embodiment of the present invention;

[0026] Figure 5 Instruction diagram of an embodiment of the present invention;

[0027] Figure 6 is the valve schematic diagram;

[0028] Figure 7 is the schematic diagram for comparing the pressure and speed curves of the new and old structures;

[0029] Referring to the attached drawings, the left traffic-limiting cylinder 1, the right traffic-limiting cylinder 2, the left support cylinder 3, the right support cylinder 4, the left sliding cylinder 5, the right sliding cylinder 6, the circular groove 7, and the V-shaped ramp groove 8. Detailed implementation manners

[0030] The present invention will be further described below in conjunction with the attached drawings.

[0031] Referring to Figures 3 to 5 , Figures 3 to 5 , which shows an embodiment of the present invention, a shock-absorbing structure for a valve stem of an electromagnetic-hydraulic control reversing valve, provided on a valve stem body in the shape of a cylinder; referring to Figure 2 , the valve stem body includes left and right symmetrically arranged traffic-limiting cylinders 1 / 2, support cylinders 3 / 4, and sliding cylinders 5 / 6. The side surface of the sliding cylinder is provided with buffer flow channels distributed along the axial direction; the end of the buffer flow channel is provided with an indented oil storage groove.

[0032] Among them, one end of the buffer flow channel is opened at the end of the side surface of the sliding cylinder 5 / 6, and the other end is arranged in the middle of the side surface of the sliding cylinder 5 / 6, that is, the oil storage groove

[0033] The oil storage groove is a circular groove 7, that is, the notch on the side surface of the valve stem body is circular and has a relatively shallow depth, being flat. The above-structured circular groove 7 can accommodate oil and can provide a space for absorbing the impact of the oil at the critical state during the switching process, effectively and smoothly transitioning the conversion of the moment of inertia. Achieving the purpose of effectively controlling the moment of inertia and smoothly reversing.

[0034] Among them, four V-shaped ramp grooves are distributed at the left end of the sliding cylinder 5 / 6, and round grooves are provided at the tops of three of the V-shaped ramp grooves 8. Four V-shaped ramp grooves 8 are distributed at the right end of the sliding cylinder 5 / 6, and round grooves are provided at the tops of two diagonal V-shaped ramp grooves 8. The V-shaped ramp grooves and round grooves on the two sliding cylinders on the valve stem body are also symmetrically arranged left and right.

[0035] Further, the buffer flow channel is a V-shaped ramp groove 8, that is, the cross-section of the buffer flow channel is V-shaped (sector-shaped), and its width shrinks from both ends of the sliding cylinder 5 / 6 towards the inner end until the inner end vertex, also in a V shape. V-shaped ramp grooves are provided at both ends of the side surface of the sliding cylinder 5 / 6, and the opposite V-shaped ramp grooves 8 are arranged staggeredly.

[0036] Preferably, the length of the V-shaped ramp groove 8 is greater than half of the axial length of the cylinder. Since the V-shaped ramp is relatively long, the back pressure of the pipeline is very small and round grooves are added. When the valve changes direction, the impact is very small and the oil cylinder operates smoothly.

[0037] See Figures 3 to 5 , the neutral function of this embodiment is PTAB (P pressure oil port; T return oil port; A inlet oil port; B outlet oil port.). The spool is a sliding cylindrical part assembled in the valve body. The side surface of the cylindrical part has appropriately designed V-shaped ramp grooves 8, which are matched with the position dimensions of the radially grooved outer surface; the chambers reserved at each step of the inner hole of the valve body; through the sliding action, the opening, closing, and control logic flow channels of the chambers are formed.

[0038] See Figure 4 , for the neutral state, the valve stem body is in the PTAB communication state under the action of the spring forces on both sides. The hydraulic oil enters from the P chamber of the main valve body into the chamber relationship designed by the inner hole of the main valve body and the outer diameter of the valve stem body, passes through the V-shaped ramp groove 8 of the valve stem body to reach the A, B, TA, and TB chambers, and then converges and flows out from the T chamber.

[0039] See Figure 5 , when shifted to the left in place, the flow direction of the hydraulic oil in the cavity hole of the main valve body is changed to P-A communication, B-T communication. The commutation action is completed.

[0040] See Figure 6 , which shows the schematic diagram of the valve stem body with the neutral function of PTAB communication, and is often used in unloading circuits and series circuits. At present, with the update of equipment and the increasingly harsh working conditions, the pressure and flow rate of the hydraulic system are getting higher and larger. It is especially suitable for precision machine tools such as grinders that have extremely high requirements for the stability of the oil cylinder. Therefore, the symmetric flow channel design of this embodiment is more rigid, has a simple structure, and provides a better guarantee for the stable support surface against harsh working conditions.

[0041] See Figure 7, in this embodiment, after changing the V-shaped groove, since the ramp length, opening, depth and angle are adjusted, especially a circular groove 8 is machined at the top (middle position) of the V-shaped ramp groove. Under the critical pressure and flow conditions of function switching, during the valve commutation process, the pipeline back pressure gradually decreases. The pressure signal during the switching of the slide body no longer has a sharp mutation as in the existing structure, and the voltage signal of the pressure sensor changes evenly and smoothly, ensuring small pipeline impact and stable operation of the oil cylinder.

[0042] Under the same pressure and flow conditions in this embodiment, the flow velocity is relatively slow and stable; with a suitable spring, the spool is more stable during switching and resetting; that is, the switching and resetting of the spool are relatively stable.

[0043] The embodiments of the present invention are described above in conjunction with the accompanying drawings and embodiments. The structures given in the embodiments do not constitute limitations to the present invention. Skilled technicians in the art can make adjustments according to needs, and various deformations or modifications within the scope of the appended claims are within the protection scope.

Claims

1. A shock-absorbing structure for the valve stem of an electromagnetic liquid-controlled reversing valve, which is provided on the valve stem body in the shape of a cylinder. The valve stem body includes a restricted cylinder body, a support cylinder body, and a sliding cylinder body that are symmetrically arranged on the left and right. It is characterized in that: The side surface of the sliding cylinder is provided with buffer channels distributed axially; the end of the buffer channel is provided with a recessed oil storage groove. Four V-shaped ramp grooves are distributed at the left end of the sliding cylinder, and circular grooves are provided at the tops of three of the V-shaped ramp grooves. Four V-shaped ramp grooves are distributed at the right end of the sliding cylinder, and circular grooves are provided at the tops of two diagonal V-shaped ramp grooves.

2. The shock absorption structure of a valve rod of an electromagnetic liquid control reversing valve according to claim 1, characterized in that: One end of the buffer channel is opened at the end of the side surface of the sliding cylinder, and the other end is provided at the middle of the side surface of the sliding cylinder.

3. The shock absorption structure of a valve stem of an electromagnetic hydraulic control reversing valve according to claim 1, characterized in that: The oil storage groove is a circular groove, that is, the notch on the side surface is circular.

4. The shock-absorbing structure of a valve stem of an electromagnetic liquid-controlled reversing valve according to claim 1, 2 or 3, characterized in that: The buffer channel is a V-shaped ramp groove, that is, the cross-section of the buffer channel is V-shaped.

5. The shock absorption structure of a valve stem of an electromagnetic hydraulic control reversing valve according to claim 4, characterized in that: The width of the V-shaped ramp groove shrinks from both ends of the sliding cylinder towards the inner end, also in a V shape.

6. The shock-absorbing structure of a valve stem of an electromagnetic hydraulic control reversing valve according to claim 4, characterized in that: V-shaped ramp grooves are provided at both ends of the side surface of the sliding cylinder, and the V-shaped ramp grooves facing each other at both ends are arranged staggeredly.

7. The shock absorption structure of a valve stem of an electromagnetic liquid control reversing valve according to claim 5 or 6, characterized in that: The length of the V-shaped ramp groove is greater than half of the axial length of the cylinder.

8. The shock absorption structure of a valve stem of an electromagnetic hydraulic control reversing valve according to claim 1, characterized in that: The V-shaped ramp grooves and circular grooves on the two sliding cylinders on the valve stem body are also symmetrically arranged left and right.

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