RU186362U1 - Honing head - Google Patents

Abstract

The utility model relates to mechanical engineering technology, to metal cutting, in particular to honing heads for the final processing of precise holes. The technical result is achieved by a honing head containing a housing with a cylindrical cavity filled with hydroplastic, in contact with the bases of the bearing blocks with abrasive blocks made with end surfaces at an angle of 2-6 degrees to the radius of the honing head and installed with the ability to move along reciprocal guides the surfaces of the housing with the axial movement of the bearing blocks simultaneously with the radial, expanding rod with a plunger installed with the possibility of influencing the hydroplastic and return springs, while the bearing blocks with abrasive bars are made in the form of sectors, with side surfaces contacting on the basis of the protrusion-cavity ", And form a prefabricated sliding cylinder. The technical result is to increase the accuracy of the form with increased surface quality of the machined hole with a maximum livestock.

Description

The utility model relates to mechanical engineering technology, to metal cutting, in particular to honing heads for finishing precision holes.

A device is known for a honing head containing a housing with radial holes in which pads with bars are placed, a push rod with elliptical surfaces of expanding elements that act on the sliders in the radial holes of the housing, and the working end of the push rod and the glass are connected by a non-self-locking thread [Copyright certificate SU No. 1174237, B24B 33/02, 1983].

The device is characterized by limited capabilities to ensure high accuracy of shape and performance when finishing holes due to the complex multi-link mechanism of pressing blocks with bars to the work surface and concentrated application of load at two points of the block and the inability to increase the number of coaxially arranged blocks with bars to increase productivity.

A device is known for a multi-row honing head comprising a housing carrying pads with abrasive blocks, expandable elements mounted to interact with blocks of bars, an expandable rod and an independent mechanism for regulating and fixing each row of bars, the housing being made in the form of a set of clips installed with the possibility of axial movement on the outer cylindrical surface. Axial movement of the bars is carried out before processing and is necessary for the convenience of regulating the position of each row of abrasive bars [Copyright certificate SU No. 1220757, B24B 33/08, 1986].

The device is characterized by limited opportunities to improve the quality of the processed surface, since it does not exclude the possibility of cutting grain getting into the risk-scratch previously cut by it, and, accordingly, the presence of deep scratches on the treated surface and the device has a complicated mechanism, which is pressed so that the blocks do not align with concentrated application of force to them, which leads to limited accuracy in the shape of the treated surface.

A known honing head comprising a housing with pusher sectors installed in it, designed for each of them to interact with expanding cones on the one hand, and with bar holders with abrasive bars made in the form of at least two helical cylindrical compression springs located at an angle to the forming head and pressed end faces to each other with Belleville springs [Patent RU 2146594, B24B 33/08, 2000].

The device is characterized by limited capabilities to ensure high accuracy of shape and performance when finishing holes due to the complex multi-link mechanism, pads with bars to the work surface are pressed and does not exclude the possibility of cutting grain getting into the scratch risk that was previously cut by it.

Known honing head, which contains a housing carrying pads with abrasive blocks, expandable elements installed with the possibility of interaction with blocks of blocks, an expanding rod and an axial movement mechanism of abrasive blocks, made in the form of a glass, in the radial holes of which on the axes are mounted to rotate around axes are rotary strips, one end of which goes into the grooves of the block, and the other into the grooves of the expansion rod and the axial movement of the blocks with bars up when moving the expansion rod from [Patent RU 2108902, B24B 33/08, 1996].

The device is characterized by limited capabilities to ensure high accuracy of shape and performance when finishing holes due to the complex multi-link mechanism of pressing blocks with abrasive bars to the work surface and concentrated application of load at two points of the block and not the possibility of increasing the number of coaxially arranged blocks with bars to increase productivity.

The closest technical solution is a honing head containing a housing, bearing pads with abrasive blocks, an expandable rod mounted to interact with blocks of blocks, an axial and radial movement mechanism of the abrasive blocks and return springs, the axial and radial movement of the abrasive blocks being made in the form hydroplastic, filling the internal cavity of the body, the expanding rod is equipped with a plunger, and the end surfaces of the bearing blocks are made at an angle of 2-6 degrees degrees to the radius of the head (Patent RU 169719, IPC V24V 33/08, 2016).

The device is characterized by limited capabilities to ensure high accuracy of shape and performance when finishing holes due to the limited contact area of the pads with abrasive blocks with the work surface and the possibility of full contact of the abrasive bars to increase productivity.

The task is to develop the design of the honing head with a simple mechanism for pressing the blocks with abrasive blocks, providing radial and axial movement of them, a distributed application of force to the blocks, with a coaxial arrangement, with the possibility of maximizing the contact area of the abrasive blocks with the treated surface.

The technical result is to increase the accuracy of the form with increased surface quality of the machined hole with maximum productivity.

The technical result is achieved by a honing head containing a housing with a cylindrical cavity filled with hydroplastic, in contact with the bases of the bearing blocks with abrasive bars, made with end surfaces at an angle of 2-6 degrees to the radius of the honing head and installed with the possibility of movement along the guide surfaces of the housing with providing axial movement of the bearing blocks simultaneously with the radial, expanding rod with a plunger, installed with the possibility of impact gidroplastmassu and a return spring, wherein the bearing pads with abrasive blocks are in the form of sectors, with lateral contact surfaces on a "protrusion-depression" and form a sliding cylinder assembly.

The essence of the technical solution lies in the fact that during axial movement of the expanding rod S _P with the plunger, when moving in a cylindrical hole of the housing, pressure is applied to the hydroplastic. This pressure of the hydroplastic through the radial openings of the housing transfers to the inner surface of the sliding cylinder, consisting of sectors of the bearing blocks with abrasive blocks and moves them in the radial direction (S _R ) - the sliding cylinder increases in diameter. The connection of the sectors of the bearing pads with abrasive bars along the lateral surfaces according to the principle of "protrusion-trench" prevents the exit of hydroplastic through the formed gap between the sectors of the bearing pads and ensures alignment and accuracy of the shape of the machined hole. Moreover, due to the inclination of the generatrix of the end conical surfaces of the sectors of the bearing blocks, at an angle of 2-6 degrees to the radius of the honing head, simultaneously with the radial movement, an axial movement (S _O ) of the sectors of the bearing blocks with abrasive bars and the axial movement of the movable cylinder occur. The simultaneous radial (S _R ) and axial movement of the bearing blocks with abrasive blocks (S _O ) eliminates the appearance of deep grooves and improves the surface quality. Hydroplastic filling the internal cavity of the housing provides uniformly distributed application of radial load, which ensures coaxial arrangement of the sectors of the bearing blocks with abrasive bars and the cylindrical shape of the movable cylinder, which guarantees the accuracy of the shape of the machined cylindrical hole and improves the quality of its surface. The cylindrical surface of the bearing blocks with abrasive blocks, made in the form of sectors and forming a movable cylinder, provides the maximum contact area of the abrasive blocks with the machined hole, which provides increased productivity.

The essence of the design of the honing head is illustrated by figures.

In FIG. 1 shows a longitudinal section through a honing head.

In FIG. 2 shows a cross section through a honing head.

The proposed design of the honing head comprises a housing 1, bearing pads 2 with abrasive bars 3, an expandable rod 4 with a plunger, with a large diameter of 5 (d ₁ ) and a smaller diameter of 6 (d ₂ ), mounted with the possibility of axial movement S _p in a cylindrical hole 7 housing 1, and with the possibility of exposure (pressure) to the hydroplastic 8, which through radial holes 9 transfers pressure to the inner surface 10 (d _o ) of the sliding cylinder, consisting of sectors of the bearing blocks 2 with abrasive bars 3, which can be changed b (increase) diameter (d _o ) and provide radial movement (S _R ), and return springs 11 return the sliding cylinder to its original position after processing.

A sliding cylinder is formed by contacting the side surfaces of the sectors of the bearing blocks 2 with abrasive bars 3, on the principle of "protrusion-trough" 12. The end conical surfaces 13 of the bearing blocks 2 with abrasive bars 3 are made at an angle of 2-6 degrees to the radius of the honing head and are installed with the possibility of movement along the response guide surfaces 14 of the housing 1 with the provision of axial movement of the carrier blocks 2 simultaneously with the radial, that is, provide axial movement of the sliding cylinder (S _O ).

The device operates as follows. After the honing head is inserted into the hole to be machined, rotation and its reciprocating movement are switched on, after which the radial and axial movement mechanism comes into effect, which carries out radial S _R and axial S _O movement of the carrier blocks 2 with abrasive bars 3. After each double stroke of the honing head the expanding rod 4 carries out axial movement S _P and the expanding rod with a plunger with a large diameter of 5 (d ₁ ), moves inside the housing 1, and presses the hydroplastic 8. This is the pressure of the hydroplastic 8 through p Adial holes 9 of the housing 1 transfers to the inner surface 10 of the movable cylinder, consisting of sectors of the bearing blocks 2 with abrasive bars 3 and moves them in the radial direction (S _R ) and the sliding cylinder increases in diameter (d _o ). The connection of the sectors of the carrier blocks 2 with abrasive bars 3 on the lateral surfaces, using the protrusion and the cavity 12 prevents the exit of hydroplastic 8 through the formed gap between the sectors of the carrier blocks 2 and ensures alignment and accuracy of the shape of the machined hole. Moreover, due to the inclination of the generatrix of the end conical surfaces of 13 sectors of the bearing blocks 2, at an angle of 2-6 degrees to the radius of the honing head, at the same time as the radial movement (S _R ), the axial movement (S _O ) of the sectors of the bearing blocks 2 with abrasive bars 3 also occurs (axial displacement (S _O ) of the movable cylinder).

The simultaneous radial (S _R ) and axial movement of the carrier blocks 2 with abrasive bars 3 (S _O ) eliminates the appearance of deep grooves and improves surface quality. Hydroplastic 8, filling the internal cavity of the housing, provides a uniformly distributed application of radial load, which ensures coaxial arrangement of the sectors of the bearing blocks 2 with abrasive bars 3 and the cylindrical shape of the movable cylinder, which ensures the accuracy of the shape of the machined cylindrical hole and improves the quality of its surface. The cylindrical surface of the bearing pads 2 with abrasive blocks 3, made in the form of sectors and forming a sliding cylinder, provides a maximum contact area of the abrasive blocks with the machined hole, which increases productivity.

The return springs 11 are designed to return the bearing pads 2 to its original position after lifting the expansion rod 4.

From the condition of incompressibility of the hydroplastic, it is possible to determine the axial displacement S _{P of the} expansion rod 4 with the plunger 5 to achieve a radial displacement S _R according to the formula:

where d _o - the diameter of the inner surface 10 of the sliding cylinder, consisting of sectors of the bearing blocks 2 with abrasive bars 3;

- длина секторов несущих колодок 2;

- the length of the sectors of the bearing pads 2;

d ₁ - a larger diameter of 5;

d ₂ - smaller diameter 6;

We calculate the limiting values of the angle of inclination α of the generatrix of the end conical surface 13 to the radius of the head. The highest value is selected from the condition of self-braking of the end conical surface 13 according to the formula

tgα _max ≤tgϕ,

where tgϕ = ƒ = 0, l is the coefficient of friction of steel on steel;

then

α _max ≤6 °;

Thus, the angle of inclination α _{max of the} generatrix of the end conical surface 13 to the radius of the head is 6 °.

The smallest limit value of the angle of inclination α _min generatrix of the end conical surface 13 to the radius of the head is determined from the condition of axial displacement (S _O ) of the movable cylinder equal to the size of the abrasive grain when moving S _R equal to the cutting depth S _R = t according to the formula:

where d _grain = 0,01 mm - the minimum size of the abrasive grain;

t _max = 0.25 mm - maximum cutting depth, mm

0.04 = tgα _min

α _min = 2 °

Thus, the angle of inclination α _min generatrix of the end conical surface 13 to the radius of the head is 2 °.

The smallest width b of the protrusion and depression 12 of the connection of the sectors of the bearing blocks 2 with the abrasive bars 3 on the lateral surfaces, to prevent the exit of hydroplastic 8 through the formed gap between the sectors of the bearing blocks 2

Where n is the number of sectors of the bearing blocks 2;

S _R - radial movement of the sectors of the bearing blocks 2.

Hydroplastic is used in two formulations:

1) 20% polyvinyl chloride, 78% dibutyl phthalate, 2% calcium stearate; melting point 135 ° C, volumetric shrinkage 12% upon cooling to 10 ° C.

2) 10% polyvinyl chloride, 88% dibutyl phthalate, 2% calcium stearate. More fluid, has a melting t of 120 ° C and a shrinkage of 10%.

Thus, the honing head containing the housing, with a cylindrical cavity filled with hydroplastic, in contact with the bases of the bearing pads with abrasive blocks made in the form of sectors, with side surfaces contacting on the principle of "protrusion-trough", and forming a sliding sliding cylinder, with end surfaces at an angle of 2-6 degrees to the radius of the honing head, and installed with the possibility of movement along the response guide surfaces of the housing with the provision of axial movement boiling pad simultaneously with radially expansible rod with a plunger mounted for exposure on gidroplastmassu and return springs, provides increased precision mold at elevated surface quality of the machined hole with maximum efficiency.

Claims (1)

Honing head, comprising a housing with a cylindrical cavity filled with hydroplastic, in contact with the bases of the bearing blocks with abrasive bars, made with end surfaces at an angle of 2-6 degrees to the radius of the honing head and mounted to move along the mating guide surfaces of the housing with axial movement of the bearing pad simultaneously with radial, expanding rod with plunger, installed with the possibility of impact on hydroplastic and return springs us for the pad, characterized in that the carrier pads with abrasive blocks are designed as sectors having lateral contact surfaces on a "protrusion-depression" and forming a sliding cylinder assembly.

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