CN105643473B - A kind of lapping device of cylindrical work outer peripheral face - Google Patents

Abstract

The invention discloses a grinding device for the peripheral surface of a cylindrical workpiece. The grinding device comprises a cuboid grinding chamber composed of a box cover and a box body; two ends of the grinding room are respectively provided with a grinding liquid inlet and a grinding liquid outlet; The grinding chamber is provided with a positioning plate parallel to the case cover, forming a space for the grinding liquid to flow under it; the positioning plate is vertically and downwardly pierced with a vortex generating column and an even-numbered column of less than or equal to 6 Workpiece positioning pins, the upper end of each workpiece positioning pin is connected to the motor located on the upper surface of the positioning plate; wherein, taking the section passing through the center line in the longitudinal direction of the positioning plate as a plane of symmetry, the axis of the vortex generating column passes through the The plane of symmetry is located at the inlet of the grinding liquid; the positioning pins of the workpiece are equally distributed on both sides of the plane of symmetry. The grinding device of the invention can simultaneously grind and polish multiple workpieces, and the processing efficiency is significantly improved.

Description

A grinding device for the outer peripheral surface of a cylindrical workpiece

technical field

The invention relates to a device for grinding or polishing, in particular to a special device for special grinding. The device utilizes the Karman vortex street principle to enhance fluidity abrasives to grind workpieces.

Background technique

Grinding and polishing the workpiece surface with flowing abrasives is a new finishing method. There are two common methods, jet polishing and abrasive flow machining.

Injection polishing is to use the polishing liquid mixed with fine abrasive particles sprayed at high speed from the small hole of the nozzle to act on the surface of the workpiece. The microscopic uneven materials are removed through the high-speed collision and shearing of the abrasive particles. By controlling the pressure and angle of the polishing liquid when spraying The polishing process that quantitatively corrects the surface roughness of the workpiece through process parameters such as injection time and injection time. For example, a "jet polishing machine" disclosed in the invention patent application with the application publication number CN103433857A, the jet polishing machine transports the base liquid and the abrasive to the ejector through the high-pressure liquid pump and the diaphragm pump respectively, and the base liquid and the abrasive are in the jet flow After turbulent diffusion and mixing in the injector, it is ejected through the nozzle of the ejector to form an abrasive liquid jet, and the abrasive liquid jet acts on the surface of the workpiece to achieve the purpose of polishing.

Abrasive flow machining, also known as extrusion grinding, is a method of finishing the surface of a workpiece using a fluid viscoelastic material (composed of polymer carriers and abrasive grains). It is mainly to force the viscoelastic material to flow over the surface of the processed part under a certain pressure, so that the abrasive particles contained in it can slip on the surface of the processed part, and then use the scraping effect of the abrasive particles to remove the surface of the processed part. The microscopic uneven material can achieve the purpose of deburring and polishing. For example, the invention patent application with the publication number CN101602182A discloses an "abrasive flow processing machine tool". When the abrasive flow processing machine tool is in use, the workpiece is clamped between the upper pusher cylinder and the lower pusher cylinder, and the workpiece passes through the workpiece to be polished. The hole in the hole is connected with two push cylinders, and fluid abrasive is installed in the push cylinder, and the two push cylinders alternately push the material to force the fluid abrasive to reciprocate and squeeze in the hole to be polished, so as to achieve the purpose of polishing.

However, the above two finishing methods still have the following deficiencies:

1. Jet polishing needs to use a high-pressure liquid pump to form a high-speed jet, which is costly; the high-speed jet is formed directly in the nozzle, causing the nozzle to be easily worn; the high-speed jet sputters heavily, and the abrasive waste is serious.

2. Abrasive flow processing usually requires a relatively complicated hydraulic system to realize the clamping of the workpiece and the action of the pushing cylinder, which is costly and has certain safety hazards.

3. Whether it is jet polishing or abrasive flow processing, the same equipment can only polish a certain part of a single workpiece at the same time, and the processing efficiency is low.

Contents of the invention

The technical problem to be solved by the present invention is to provide a grinding device for the peripheral surface of a cylindrical workpiece. The grinding device can simultaneously grind and polish the peripheral surfaces of multiple workpieces, and the processing efficiency is significantly improved.

The technical scheme that the present invention solves the problems of the technologies described above is:

A grinding device for the peripheral surface of a cylindrical workpiece, the grinding device comprises a cuboid grinding chamber composed of a box cover and a box body, the two ends of the grinding room are respectively provided with a grinding liquid inlet and a grinding liquid outlet;

The grinding chamber is provided with a positioning plate parallel to the case cover, forming a space for the grinding liquid to flow under it; the positioning plate is vertically and downwardly pierced with a vortex generator from the grinding liquid inlet to the grinding liquid outlet. column and an even number of workpiece positioning pins less than or equal to 6, and the upper end of each workpiece positioning pin is connected to the motor located on the upper surface of the positioning plate; The axis of the spin column passes through the plane of symmetry and is located at the entrance of the grinding fluid; the positioning pins of the workpiece are equally distributed on both sides of the plane of symmetry, and when the grinding fluid flows through the grinding chamber, the Reynolds number When it is 47-10 ⁵ , the centers of the workpiece positioning pins are respectively located in the middle of a line vortex of the double row line vortex generated behind the vortex generating column; at the same time, the grinding chamber and the vortex inside it The structural parameters and positional relationship of the generating column and the positioning pin of the workpiece meet the following requirements:

d _g ≤0.6d (Ⅰ)

B/d＝6～10 (Ⅱ)

H=βd (Ⅳ)

In the above formulas (I) to (IV), d is the outer diameter of the vortex generating column, d _g is the outer diameter of the workpiece to be machined, B is the width of the grinding chamber, and L is the diameter of the two adjacent columns located on the same side of the symmetry plane. The distance between the workpiece positioning pins, H is the distance between the workpiece positioning pins and the symmetrical plane, α is a constant, and α=0.73～0.78, β is a constant, and β=1.0～2.2, Sr is Strouhal Number, and Sr=0.21.

The above-mentioned grinding device can form a grinding system, which includes an infusion pump, an electric regulating valve, an electromagnetic flowmeter and a grinding device for the outer peripheral surface of the above-mentioned cylindrical workpiece sequentially connected in series.

The working process of grinding device of the present invention is briefly described as follows:

Set the parts to be processed on the positioning pin of the workpiece, adjust the flow rate of the grinding liquid, and make the Reynolds number Re reach 47-10 ⁵ , and then the polishing of the workpiece can be realized.

The Reynolds number Re of the grinding liquid is obtained by the following formula:

Among them, v is the flow velocity of the grinding liquid, D is the hydraulic diameter of the grinding liquid in the grinding chamber, and μ is the dynamic viscosity of the grinding liquid.

The present invention has following beneficial effect:

1. When the abrasive liquid flows through the vortex generating column, the two sides of the vortex generating column will periodically shed the double row linear vortex (ie Karman vortex) with opposite rotation direction and regular arrangement, and in the scheme of the present invention The workpiece positioning pin is just located in the middle of the "line vortex", so multiple workpieces can be ground at the same time, and the processing efficiency is significantly improved.

2. After the abrasive liquid flows through the vortex generating column, the energy carried by it gathers in the vortex formed behind it, so the abrasive grains carried by the vortex hit the surface of the workpiece at high speed to complete the polishing of the workpiece, which not only makes full use of the abrasive liquid The energy carried effectively improves the energy efficiency of the device, and also reduces the wear of the grinding fluid on the parts of the device itself.

3. The Karman vortex can be formed at a low Reynolds number Re, so the head and flow of the pump for transporting the grinding liquid do not need to be large, which can effectively reduce the cost of the device and improve the safety of the device.

Description of drawings

Fig. 1～3 is the structural representation of a specific embodiment of grinding device of the present invention, and wherein Fig. 1 is front view (section), and Fig. 2 is A-A sectional view among Fig. 1, and Fig. 3 is left side view; B is the width of the grinding chamber, L is the distance between two adjacent workpiece positioning pins on the same side of the symmetrical plane, and H is the distance between the workpiece positioning pins and the symmetrical plane.

Fig. 4 is a schematic perspective view of the three-dimensional structure of the embodiment shown in Figs. 1-3; Fig. 5 is an enlarged view of part M in Fig. 4 .

Fig. 6 is a schematic diagram of the positional relationship between the vortex generating column and the workpiece positioning pin in the embodiment shown in Figs. 1-3.

Fig. 7 is a schematic diagram of the principle of forming a Karman vortex street polishing workpiece by the abrasive liquid in the embodiment shown in Figs. 1-3.

Fig. 8 is a nephogram of the velocity distribution of the polishing liquid in the embodiments shown in Figs. 1-3.

Fig. 9 is a schematic diagram of the positional relationship between the vortex generating column and the workpiece positioning pin in the grinding chamber in another specific embodiment of the grinding device of the present invention.

Fig. 10 is the velocity distribution nephogram of grinding liquid in the embodiment shown in Fig. 9

Fig. 11 is a schematic diagram of a grinding system composed of the grinding devices shown in Figs. 1-3.

detailed description

example 1

Referring to Figures 1 to 5, the grinding chamber 5 of the grinding device is a rectangular box, the top of which is covered with a box cover 5-1, and the walls of the two ends of the grinding chamber 5 are respectively provided with a grinding liquid inlet 5-2 and a grinding liquid Exit 5-3. A positioning plate 6 parallel to the case cover 5-1 is provided in the grinding chamber 5 near the position of the case cover 5-1, and the positioning plate 6 is supported on a shoulder provided on the inner wall of the grinding chamber 5; The space is the space through which the grinding liquid flows, and the dimensions of this space are: width * height (distance from the bottom of the grinding chamber to the lower side of the positioning plate) = 600mm * 400mm (hydraulic diameter D is 480mm), length = 1600mm.

Referring to Figures 1 to 5 and in conjunction with Figure 6, a vortex generating column 7 perpendicular to the positioning plate 6 is provided at a position 300 mm below the positioning plate 6 and the grinding liquid inlet 5-2, and the outer diameter of the vortex generating column 7 is It is 100mm, and is fixed on the locating plate 6 by the coaxial post positioning pin 7-1 that passes through it inside; take the longitudinal section that passes through the center line of the locating plate 6 lengthwise as the plane of symmetry, then the described The axis of the positioning pin 7-1 of the generating column is on the symmetrical plane; the rear of the vortex generating column 7 is provided with two groups of workpiece positioning pins 8 respectively located on both sides of the symmetrical plane; each group of workpiece positioning pins 8 They are all composed of three pins passing through from the top of the positioning plate 6 to the bottom of the positioning plate, and each workpiece positioning pin 8 is connected with a motor 9 located on the side of the positioning plate, and the end of the motor 9 away from the output shaft is supported on the box cover. The lower side of the 5-1 is used to fix the positioning plate 6; the case cover 5-1 is fixed on the top of the grinding chamber 5 by screws.

Referring to Fig. 6, the two groups of workpiece positioning pins 8 are numbered respectively, and the three in one group are respectively numbered as I, II, and III, and the three in the other group are respectively numbered as IV, V, and VI; 8 The distance from the grinding liquid inlet 5-2 is the abscissa, and the distance from the symmetrical plane is the ordinate, then the positions of the two sets of workpiece positioning pins 8 can be represented by the following coordinates: I (590,100), II (945,150), Ⅲ (1300, 130), Ⅳ (750, -150), Ⅴ (1105, -170), Ⅵ (1460, -140), where the negative and positive values in the ordinate indicate the difference between side, the coordinate value unit is mm. When the grinding liquid flows through the grinding chamber 5 and the Reynolds number is 90, the centers of the workpiece positioning pins 8 distributed according to the above coordinates are respectively located in the middle of one of the double-row linear vortices generated behind the vortex generating column 7 .

Referring to Fig. 11 in combination with Fig. 4, a grinding system is constructed by combining the grinding device 11 in this example with the liquid storage tank 1 and the infusion pump 2, the inlet of the infusion pump 2 communicates with the bottom of the liquid storage tank 1, and the outlet connects with the grinding The grinding liquid inlet 5-2 of the device 11 is connected, and the grinding liquid outlet 5-3 of the grinding device 11 is connected with the liquid storage tank 1 . The pipeline between the outlet of the infusion pump 2 and the grinding liquid inlet 5-2 of the grinding device 11 is connected in series with an electric regulating valve 3 and an electromagnetic flowmeter 4 to regulate and monitor the flow of the grinding liquid, so as to obtain a suitable flow rate.

The formula of the grinding liquid in this example is as follows:

Brown corundum powder 30% (average particle size is 18.6μm), oily liquid (63% deionized water, 0.5% sodium polyacrylate, 7% sodium bicarbonate, 21% No. 46 mineral oil, 8.5% emulsifier Span 80) 70%, the density is 1620kg/m ³ , and the dynamic viscosity is 0.008Pa.s; the above percentages are mass percentages.

The working principle of the grinding device of the present invention is briefly described below in conjunction with the accompanying drawings:

Referring to Fig. 7, when the Reynolds number Re of grinding liquid fluid reaches 50, can form stable, somewhat regular, the vortex (Karman vortex street phenomenon) that the direction of rotation is opposite, both sides alternately falls off at the rear of vortex generation column; The vortex can entrain the abrasive grains in the abrasive liquid and collide with the workpiece 10 at a speed much higher than the average flow velocity of the abrasive liquid, so as to realize the polishing treatment on the surface of the workpiece 10 .

The numerical simulation software Fluent16 is used to analyze the grinding liquid fluid in order to verify the effect of the grinding device in this example:

The calculation conditions are: a steady-state laminar flow model, input the density and dynamic viscosity of the abrasive fluid, the momentum item of the flow equation is discretized by the second-order upwind method, the pressure item is discretized by the standard format, and the SIMPLE algorithm is used to solve it, and other settings are defaulted. The outer diameter of the workpiece 10 is set to 40mm, and the grinding fluid flows through the vortex generating column 7 at a speed of 1.5m/s (Re is 90 at this time).

Fluent16 software was used to simulate the flow of the grinding liquid in the grinding chamber 5 in this example, and a cloud map of the flow velocity distribution of the grinding liquid was derived (see FIG. 8 ).

Figure 8 shows that the maximum velocity of the flow area behind the vortex generating column 7 is 2.94m/s, which is much higher than the inlet velocity of the grinding chamber 5. Obviously, the average shear stress on the surface of each workpiece increases, and the polishing efficiency is significantly improved.

Example 2

Referring to Fig. 9, in this example, the Reynolds number of the grinding chamber 5 flowing through the grinding fluid is designed to be 60, and the positions of the two groups of workpiece positioning pins 8 can be represented by the following coordinates: I (570,130), II (920,190), III (1290,215 ), Ⅳ (740, -180), Ⅴ (1110, -200), Ⅵ (1480, -210); in this example, the implementation method other than the above is the same as Example 1.

The numerical simulation software Fluent16 is used to analyze the grinding liquid fluid in order to verify the effect of the grinding device in this example:

The calculation conditions are: a steady-state laminar flow model, input the density and dynamic viscosity of the abrasive fluid, the momentum item of the flow equation is discretized by the second-order upwind method, the pressure item is discretized by the standard format, and the SIMPLE algorithm is used to solve it, and other settings are defaulted. The outer diameter of the workpiece 10 is set to 40mm, and the grinding liquid flows through the vortex generating column 7 at a speed of 1m/s (Re is 60 at this time).

Fluent16 software was used to simulate the flow of the grinding liquid in the grinding chamber 5 in this example, and a cloud map of the flow velocity distribution of the grinding liquid was derived ( FIG. 10 ).

Referring to Fig. 10, the maximum velocity of the flow area behind the vortex generating column 7 is 1.75m/s, which is much higher than the inlet velocity of the grinding chamber 5. Obviously, the average shear stress on the surface of each workpiece increases, and the polishing efficiency is significantly improved.

Claims (2)

1. A grinding device for a cylindrical workpiece peripheral surface, the grinding device comprises a cuboid grinding chamber made up of a case cover and a casing, the two ends of the grinding chamber are respectively provided with a grinding liquid inlet and a grinding liquid outlet; The grinding chamber is provided with a positioning plate parallel to the case cover, forming a space for the grinding liquid to flow under it; the positioning plate is vertically and downwardly pierced with a vortex generator from the grinding liquid inlet to the grinding liquid outlet. column and an even number of workpiece positioning pins less than or equal to 6, and the upper end of each workpiece positioning pin is connected to the motor located on the upper surface of the positioning plate; The axis of the spin column passes through the plane of symmetry and is located at the entrance of the grinding fluid; the positioning pins of the workpiece are equally distributed on both sides of the plane of symmetry, and when the grinding fluid flows through the grinding chamber, the Reynolds number When it is 47-10 ⁵ , the centers of the workpiece positioning pins are respectively located in the middle of a line vortex of the double row line vortex generated behind the vortex generating column; at the same time, the grinding chamber and the vortex inside it The structural parameters and positional relationship of the generating column and the positioning pin of the workpiece meet the following requirements: d _g ≤0.6d (Ⅰ) B/d＝6～10 (Ⅱ) <mrow><mi>L</mi><mo>=</mo><mi>&amp;alpha;</mi><mfrac><mi>d</mi><mrow><mi>S</mi>mi><mi>r</mi></mrow></mfrac><mo>-</mo><mo>-</mo><mo>-</mo><mrow><mo>(</mo><mi>I</mi><mi>I</mi><mi>I</mi><mo>)</mo></mrow></mrow> H=βd (Ⅳ) In the above formulas (I) to (IV), d is the outer diameter of the vortex generating column, d _g is the outer diameter of the workpiece to be machined, B is the width of the grinding chamber, and L is the diameter of the two adjacent columns located on the same side of the symmetry plane. The distance between the workpiece positioning pins, H is the distance between the workpiece positioning pins and the symmetrical plane, α is a constant, and α=0.73～0.78, β is a constant, and β=1.0～2.2, Sr is Strouhal Number, and Sr=0.21. 2. A grinding system comprising an infusion pump connected in series, an electric regulating valve, an electromagnetic flowmeter and the grinding device for the outer peripheral surface of a cylindrical workpiece according to claim 1.