RU2095566C1 - Impact-action device - Google Patents

Abstract

FIELD: rock-crushing equipment. SUBSTANCE: this relates to devices for crushing rocks and artificial materials, for loosening frozen and compacted filled earth and can be used in mining industry, metallurgy and construction, and also in designing pile-driving and stamping hammers. This impact-action device or hammer is simple in design, compact in size and easy to manufacture. It possesses high power due to fact that overflow chamber in it is connected by passage in body through non-return valve with cocking chamber having hydraulic accumulator. Outer surface of circular valve is made in the form of four-stage cylinder. Its first stage at side of cocking chamber is of smallest diameter. Second stage is provided with sealing protrusion and is of diameter which is less than diameter of third stage but larger than diameter of fourth stage adjacent to side surface of stepped opening in body. EFFECT: high efficiency. 2 dwg

Description

 The invention relates to devices for the destruction of rock and artificial materials, loosening of frozen and compaction of bulk soils and can be used in mining, metallurgy and construction, as well as the creation of piling and stamping hammers.

 A percussion device / 1 / is known, including a housing forming an idle chamber with a piston by a striker, constantly in communication with a pressure source and a hydraulic accumulator, and a working chamber communicated alternately with the idle chamber or with a drain line.

 This device has a significantly higher efficiency and frequency of impacts, but the piston-hammer, in addition to the main function, plays the role of a slide valve that controls the fluid flow inside the device. For normal operation of the device, the gaps between the inner surface of the housing and the outer surface of the piston-hammer must be within 0.03-0.06 mm, while for the hammer with its direct purpose, gaps of 0.1-0.2 mm are allowed, i.e. three times more. Therefore, even a small wear of the piston-drummer and the guides of the housing can lead to disruption of the device, while for the intended purpose the piston-drummer could work for a very long time.

 In addition, for supplying fluid from the distributor to the working chambers, extended small cross-section channels are made in the housing, which, on the one hand, complicates the manufacturing technology, and on the other, reduces the efficiency of the device due to hydraulic losses in these channels. And, finally, due to the fact that the collision with the tool in this device occurs after the spool valve is switched, then a force will act against the piston-hammer during the time from switching the spool valve to the impact, decreasing its speed .

 The device / 2 / closest in technical essence to the proposed invention is known, comprising a housing, in the axial step hole of which a piston-hammer is coaxially placed along its axis and an annular step valve with an axial step bore enveloping it, the diameter of which is equal to the diameter of the piston protrusion of the piston - hammers, together forming a battery chamber filled with compressed gas, an overflow chamber in communication with a drain line, a pressure chamber in communication with a pump and in communication with last cocking chamber.

 However, it is not reliable enough, it has a reduced shock frequency and efficiency due to the incomplete use of the energy of the working fluid coming from the pump during the stroke of the hammer.

 The purpose of the invention is to increase the reliability, frequency of shock and efficiency of the device.

The essence of the invention lies in the fact that, in contrast to the known technical solution according to the invention, the overflow chamber is in communication with a charging chamber including a pressure accumulator through a check valve in a channel in the housing, and the annular valve on the outer side surface has four cylindrical steps, of which the first is from the charging chamber has the smallest diameter, the diameter of the second stage, having at its end the sealing lip is smaller than the diameter of the third stage, but larger than the diameter of the fourth stage, conjugated with a cylindrical surface of the stepped opening of the housing, and in the housing opposite the first and second stages of the annular valve, a stepped cylindrical bore is made, the diameter of the larger stage of which is equal to the diameter of the second stage of the annular valve, and the diameter of the smaller stage of the said bore is slightly larger than the diameter of the first stage of the annular valve, the length being longer the steps of this bore are less than the length of both the first and second steps of the annular valve and said body bore is determined by the ratio eat
l ₁ l ₂ <l ₃ l ₄ l ₅ <l ₃
where l _{1 is the} distance from the end surface separating the first and second steps of the body boring to the plane separating the cocking and pressure chambers, m;
l _{2 the} total length of the second and third valve stages, m;
l _{3 the} length of the first step of the stepwise boring of the body, m;
l _{4 the} distance from the end surface separating the first and second stages of the housing bore to the end surface of the housing groove that is farthest from the cocking chamber side and communicates with the drain line, m;
l ₅ distance from the end face of the second stage of the valve to the edge of the radial channels closest to the side of the cocking chamber in the valve body communicating with the overflow chamber with the said housing groove, m

 The technical result obtained by carrying out the invention consists in increasing the reliability, frequency of impacts and efficiency of the device.

 In FIG. 1 is a schematic diagram of a device; in FIG. 2 enlarged image of the valve.

The impact device consists of a housing 1, in the guides 2 and 3 of which a piston-hammer 4 with a piston protrusion 5 is mounted movably along its axis. The lower (according to the drawing) rod 6 has a diameter D ₁ greater than the diameter D _{2 of} its upper rod 7. A piston protrusion 5 with its cylindrical surface with a diameter of D ₃ mates with the surface of the stepped bore of the housing 1, while the cavity formed by the internal bore of the housing 1 and the outer surface of the piston-hammer 4 is divided into two chambers: cocking 8 and mobile 9, which communicate with each other at the open position of the annular valve 10. The cocking chamber 8 through channels 11, 12 and 13 is in communication with the accumulator 14 and the pressure chamber 15, communicated through channel 16, the pressure line 17 with a pressure source 18. Overflow chamber 9 through channels 19 and 20, the check valve 21, channels 22 and 23 are in communication with the accumulator 14, and through channels 12 and 11 with a cocking chamber 8. In addition, the overflow chamber 9 through channels 23 in the valve body 10, an annular groove 24, channel 25 communicates with a drain line 26. In the upper part of the housing 1 is a battery chamber 27, ennaya compressed gas, which includes a rear rod 7 striker 4. The outer surface of annular valve 10 has four cylindrical stage. The diameter D _{4 of the} first stage 28 is smaller than the diameter D _{5 of the} second stage 29, at the end of which a sealing lip 30 is located. The diameter D _{5 of the} second stage 29 is smaller than the diameter D _{6 of the} third stage 31, but larger than the diameter D _{7 of the} fourth stage 32, which is associated with the side surface step boring 33 of the housing 1. The diameter D _{6 of the} third stage 31 is slightly smaller than the diameter D _{8 of the} pressure chamber 15. In the housing 1 from the side of the cocking chamber 8 there is an annular step boring having two stages, the first of them 24 has a diameter equal to the diameter of the second stage 29 count tsevogo valve 10 and the second stage 35 has a bore diameter D ₉ somewhat larger than the diameter D ₄ of the first stage 28 of the valve 10. In this stage the length of the annular bore 34 smaller than the length of both the first 28 and second 29 annular valve stage 10. The length of the valve stages 10 and the ring bore of the housing 1 are connected by the relations
l ₁ l ₂ <l ₃ and l ₄ l ₅ <l ₃ ,
where l _{1 is the} distance from the end surface separating the first 34 and second 35 steps of the body boring to the plane separating the incoming 8 and pressure 9 of the chamber;
l _{2 the} total length of the second 29 and third 31 stages of the valve 10;
l _{3 the} length of the first stage 34 of the bore of the housing 1;
l _{4 the} distance from the end surface separating the first 34 and second 35 steps of the housing boring to the upper (according to the drawing) end surface of the groove 24 of the housing 1;
l _{5 the} distance from the end surface separating the first 34 and second 35 stages of the bore of the housing 1 to the lower (according to the drawing) edge of the radial channels 23 in the body of the valve 10.

 To prevent leakage of liquid outward and its flows between the chambers, soft seals 36, 37, 38, 39 and 40 are installed.

 The device operates as follows.

In the initial state, the hammer 4 and the valve 10 are in the lowest position (according to the drawing). The battery chamber 27 is filled with compressed gas. Cocking 8 and pressure chamber 15 are interconnected by a wide circular slit, the width of which is equal to B l ₂ l ₁ . Overflow 9 chamber through radial channels 23, groove 24, channel 25 is in communication with a drain line 26.

где D₁ и D₂ диаметры штока 6 и поршня 5 ударника.The liquid from the pressure source 18 along the pressure line 17 of the channel 16 enters the pressure chamber 15, from where, through a slot B wide, the channel 11 enters the cocking chamber 8, in which the liquid pressure increases. Under the influence of this pressure on the annular area G of the piston 5, equal to

where D ₁ and D _{2 the} diameters of the rod 6 and piston 5 of the hammer.

 Drummer 4 moves up (according to the drawing). The liquid from the overflow chamber 9 through the grooves 23, the annular groove 24, the channel 25, the drain line 26 enters the drain tank. The gas pressure in the battery chamber 27 will increase due to a decrease in the volume of gas when the rod 7 enters it.

где P_ж давление жидкости в напорной 15 и взводящей 6 камерах;
D₅, D₇ диаметры ступеней 29 и 32 клапана 10 соответственно.At this moment, the cocking chamber 8 is isolated from the overflow chamber 9 by the valve 10. The lateral surface of the step 29 of the valve 10 is mated to the surface of the step 34 of the stepwise boring of the housing 1, and the sealing lip 30 of the valve 10 is in contact with the end surface of the stepwise boring of the housing 1. On the valve 10 from the side pressure chamber 15 acts axial force P _CL1 equal to

where P _W the fluid pressure in the pressure 15 and cocking 6 chambers;
D ₅ , D _{7 the} diameters of the stages 29 and 32 of the valve 10, respectively.

 At the end of its upward movement, the hammer 4, by piston 5 entering the annular bore of the valve 10 and touching its end face with the end of the aforementioned bore, carries the valve 10 behind itself just before the sealing protrusion 30 of the stage 29 of the valve 10 leaves the stage 34 of the stepwise bore of the housing 1 The radial channels 23 are blocked by the surface 33 of the housing 1 bore, and the stage 31 with its upper end enters the pressure chamber 15. From then on, the overflow chamber 9 will be isolated from the drain line, and the cocking 8 and pressure 15 of the chamber b FLS are interconnected by a slot formed by the lateral surfaces of the pressure chamber 15 and stage 31 of the valve 10.

The width of this gap B ₁ is equal to
B ₁ 1/2 (D ₈ D ₆ ),
where D _{6 the} diameter of the third stage of the valve;
D ₈ diameter of the pressure chamber.

где Δp₁ перепад давления жидкости между напорной 15 и взводящей 8 камерами;
D₆ диаметр ступени 31 клапана 10;
D₇ диаметр ступени 32 клапана 10.This gap for the fluid flow between the said chambers represents a significant resistance, which is expressed by the pressure drop Δp _{1 of the} fluid between these chambers. Under the action of this differential pressure on the valve 10 from the side of the pressure chamber 15, a force determined by the expression

where Δp _{1 the} pressure drop between the pressure head 15 and cocking 8 chambers;
D _{6 the} diameter of the stage 31 of the valve 10;
D _{7 the} diameter of the stage 32 valve 10.

 With the further movement of the hammer 4 together with the valve 10 upwards, when the channels 23 connecting the overflow chamber 9 to the drain line are closed, the fluid from this chamber through channels 19 and 20, the check valve 21, and the accumulator 14 will enter the channels 22 and 13.

где P₀ давление газа в газовой камере 27;
P_ж давление жидкости в переливной камере 9;
D₁, D₂ диаметры нижнего 6 и верхнего штоков 4 ударника.After the sealing protrusion 30 of the stage 29 of the valve 10 comes out of the stage 34 of the housing 1 bore, the fluid pressure in the overflow 9 and cocking 8 chambers becomes approximately the same, and the balance of forces acting on the hammer 4 is disturbed, and the resultant of the forces acting on the hammer 4 will be directed down i.e. against his movement, and its magnitude P _beats will be equal to

where P _{0 is} the gas pressure in the gas chamber 27;
P _W the fluid pressure in the overflow chamber 9;
D ₁ , D ₂ diameters of the lower 6 and upper rods 4 of the hammer.

 Under the action of this force, the drummer 4 is first braked, and then accelerates down to strike, making a working stroke.

 During this braking of the striker 4, its kinetic energy is converted into potential gas compression energy in the accumulator 14, which, during the subsequent working stroke, is again converted into the kinetic energy of the striker. The valve 10 until the stop of the hammer 4 in the highest position moves together with the latter, and with the start of the movement of the hammer 4 downward, the valve 10 continues to move up until the piston protrusion 5 of the hammer 4 comes out of the annular bore of the valve 10. After the separation of the piston the protrusion 5 and the bore of the valve 10, between the lower end of the valve 10 and the upper end of the stage 34 of the annular bore of the housing 1, a wide gap is formed, through which the liquid from the cocking 8 and pressure 15 chambers, as well as from the accumulator 14 will come s cavity in the releasing of the top part 4 of the piston 5 impactor overflow chamber 9.

где P_ж давление жидкости в гидравлической полости.From the moment of closing the drain channels 23 in the cocking 8 and overflow 9 chambers, the fluid pressure is determined, determined by the accumulator 14, which is greater than the maximum fluid pressure during cocking of the hammer 4, therefore, in addition to the force from the side of the gas chamber 27, it will act on the hammer 4 during acceleration in the same direction, the fluid pressure force P _W , equal in magnitude

wherein P _w fluid pressure in the hydraulic chamber.

The valve 10 after separation with the hammer 4 under the action of the force P _CL2 from the pressure chamber 15 will begin to move down to close. The value of this force P _{kl2 is} given above.

По мере увеличения скорости ударника 4 переток жидкости между упомянутыми полостями увеличивается, поэтому ширина упомянутой щели будет возрастать до конца рабочего хода ударника 4.This downward movement of the valve 10 will occur until an annular gap is formed between the end face of the stage 28 of the valve 10 and the end defining the stages 34 and 35 of the housing 1, at which the differential pressure Δp ₂ between the charging 8 and overflow 9 chambers does not balance the force acting on the valve 8 from the pressure side 15 of the chamber. This condition can be expressed by the equation

As the speed of the striker 4 increases, the fluid flow between the said cavities increases, so the width of the mentioned slit will increase until the end of the stroke of the striker 4.

The pressure drops Δp ₁ and Δp ₂ are no more than 3 of the liquid pressure in the pressure 15 and cocking 8 chambers and, given that these pressure drops exist only during the stroke of the hammer 4, the energy loss is negligible, i.e. the efficiency of the device is high.

 At the beginning of the working stroke, while the speed of the hammer 4 is small, the working fluid from the pressure source 18 will mostly flow into the accumulator 14, and at the end of the working stroke, in addition to the liquid from the pressure source, almost all the liquid stored at the beginning also enters the overflow chamber 9 stroke in the accumulator 14.

After impact of the striker 4 into the obstacle, the material being processed stops, the flow of fluid to the overflow chamber 9 stops, since its volume becomes constant, the pressure drop Δp ₂ between chambers 8 and 9 disappears. The difference is Δp ₁ . between pressure 15 and cocking 8 chambers remains, since the fluid flow between these chambers remains constant. The fluid with a stationary hammer 4 enters the accumulator 14. At that time, only one force will be applied to the valve 10, the pressure force of the liquid from the pressure chamber 15, determined by the pressure drop Δp ₁ Under the action of this force, the valve 10 moves down; first, the sealing protrusion 30 of the stage 29 enters the cylindrical stage 34 of the housing bore, thereby separating the cocking 8 and the overflow 9 of the chamber, and then the opening of the channels 23 begins, communicating the overflow chamber 11 with the drain line 26, and at the same time a gap is formed between the upper end of the valve stage 31 10 and the end face separating the cocking 8 and pressure chamber 15. Due to the fact that by the end of the stroke in the hydraulic cavity of the accumulator 14 there remains a small supply of working fluid, the fluid pressure in the cocking 8 and pressure chamber 15 will be close to the maximum value.

 Under the influence of this pressure on the front end of the piston 5, the movement of the striker 4 starts up idling.

где Q_нас производительность гидронасоса источника давления 18, аккумулятор 14 начнет разряжаться.At the first moment, while the speed is small, part of the fluid from the pressure source 18 will flow into the accumulator 14 even after the impactor speed V _beats. reaches a value equal to

where Q _{us the} performance of the hydraulic pump of the pressure source 18, the battery 14 will begin to discharge.

 Since the speed of cocking the striker is small, and the acceleration acceleration is large, the amount of liquid entering the battery is small, so the battery is discharged at the very beginning of the acceleration path, and until the end of idle of the striker 4, the battery will remain discharged. Next, the cycle of the device is repeated.

 Thus, in the platoon chambers 8 and pressure chamber 15, the liquid pressure close to the maximum will be maintained during the entire working cycle, which ensures maximum device power with minimum drive power and device size. At the same time, the hydraulic pump of the pressure source 18 operates at almost constant pressure, which favorably affects the operation of both the pump itself and ballast hydraulic equipment and pipelines, especially hoses.

 The device provides the use of the kinetic energy of the projectile stored by it at idle for subsequent acceleration of the projectile during operation.

 And finally, due to the large cross-sections through which the fluid flows between the chambers, both during idle and during working moves, energy losses due to resistances are negligible, therefore, the efficiency of the device is high.

Claims (1)

The impact device, comprising a housing, in the axial step hole of which the piston-hammer is coaxially placed along its axis and an annular step valve with an axial step-boring enveloping it, the diameter of the largest stage of which is equal to the diameter of the piston protrusion of the piston-hammer, together forming a battery pack filled with compressed gas connected with a drain line overflow, connected with a pressure head pump and communicated with the last cocking chamber, characterized in that the overflow chamber Kana scrap in the body through a check valve is connected to a cocking chamber including a hydraulic accumulator, and the outer side surface of the annular valve is made in the form of a four-stage cylinder, the first closest from the side of the cocking chamber, the step of which has the smallest diameter, and the second step in turn of the valve on the cocking chamber facing the end face is provided with a sealing protrusion and has a diameter less than the diameter of the third stage, but larger than the diameter of the fourth stage, mated along the lateral surface of the step opening casing, and in the casing opposite the first and second stages of the annular valve, a stepped cylindrical bore is made, the diameter of the larger stage of which is equal to the diameter of the second stage of the annular valve, and the diameter of the lower stage of the said bore is slightly larger than the diameter of the first stage of the annular valve, while the length of the larger stage of this bore less than the length of both the first and second stages of the annular valve, and the ratio of the lengths of the stages of the annular valve and the said bore is determined by the following expression
l ₁ -l ₂ <l ₃ , l ₄ -l ₅ <l ₃ ,
where l _{1 is the} distance from the end surface separating the larger and smaller steps of the body boring to the plane separating the cocking and pressure chambers, m;
l _{2 the} total length of the second and third stages of the valve;
l _{3 the} length of the greater stage of the body boring, m;
l _{4 the} distance from the end surface separating the larger and smaller steps of the housing bore to the end surface of the housing groove that is farthest from the cocking chamber and communicates with the drain line, m;
l _{5 the} distance from the end face of the second stage of the valve to the edge of the radial channels closest to the side of the cocking chamber in the wall of the fourth stage of the valve, communicating overflow chamber with the said groove of the body, m

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