DE2118936A1 - BRAKING DEVICE ON CONTROLLABLE HYDRAULIC MOTORS - Google Patents

Description

BRAKE DEVICE ON CHANGEOVER LANE HYDRAULIC MOTORS The invention refers to reversible hydraulic motors that are designed to handle a load with a large Inertia are coupled, and is intended to provide smoother and more accurate braking of such Enabling motors than the systems available up to now allow.

The drive motors of cranes and digging machines to bring about the swiveling movements of the machines and usually the deceleration is effected by that the directional valve of the reversible hydraulic motor can be set in opposite directions Sets the direction of the swivel that is currently taking place, so that the motor oine braking Force in the opposite direction, or one on the output shaft The brake attached to the hydraulic motor is operated, usually a disc brake.

None of these braking devices work satisfactorily. When hiring of the directional valve in the opposite direction to braking is the response time, i.e. the time between the changeover of the directional valve and the onset of the braking effect, extremely short and can be considered practically zero.

It is therefore difficult to maintain the standstill position with such a braking to smell the braking part.

This rapid braking causes both the hydraulic system as well as the part operated by the hydraulic motor and parts coupled to it exposed to great stress. Since the pump in the hydraulic system that one used to operate the hydraulic motor, also used to brake the same will,. In addition, the capacity of the pump cannot operate during braking be used by other hydraulic parts, but this is desirable can be, for example, when you are working with a crane or a digging machine panning initiates or performs other movements.

Thus, the pump must be greatly oversized or with auxiliary pumps can be completed if this possibility when braking by setting the directional valve to insist in the opposite direction, or else you have to take advantage of it forego being able to perform other functions while panning. With both Alternatives are of course combined with considerable disadvantages. Also for that If you have a brake on the output shaft of the hydraulic motor, you have to one with a short reaction time and high loads on the hydraulic system and of the mechanical parts. In addition, the brake is quite a significant one Expenditure.

For the purpose of eliminating the aforementioned disadvantages through expansion of the hydraulic system and - at relatively low additional costs - the condition one soft and precise braking of a reversible hydraulic motor, which is connected to a Load is coupled with great inertia and inflow and outflow lines for the hydraulic fluid and a main control valve connected to the lines to direct the flow of hydraulic fluid to drive the engine in one or the other direction and to activate the motor by short circuit which has lines, according to the invention, a braking device is attached to such a device Motor characterized in that in each of the lines a means of one from Machinists can be operated any common switching element to control the Throttle effect in the short circuit adjustable throttle valve is attached and a check valve connected in parallel with this, which controls the flow of the hydraulic Liquid allowed in the direction of flow.

To illustrate the invention in terms of its execution and Function and to explain the advantages achieved by the invention is a Implementation of the invention below with reference to the accompanying drawings described in more detail.

1 shows the circuit of a hydraulic system with a reversible hydraulic motor made according to the invention; Fig. 2 shows a vertical Average one of two belonging to the hydraulic system according to the invention Valve devices; and FIG. 3 shows a detailed section of the valve device in FIG. 2.

A reversible hydraulic motor 102 to a wet with large Inertia is coupled, for example a large swing mass, as in cranes and digging machines occurs, has lines 11V and IIH for supply and discharge of hydraulic fluid to or from the hydraulic motor. Each of the lines is about a. Valve device 12V or 12H, which will be described in more detail below be: should, to a directional valve 13, which acts as the main control valve of the hydraulisehen System works, and connected to a line 14, which leads to an oil tank 15. A motor-driven pump 16 is connected to its suction line 17 via a filter 18 the oil tank 15 is connected and, with its pressure line 19, firstly to a line 20 I1 connected via a conventional overflow valve 21 to the Oil tank 15 is connected, secondly via a flow in the direction of transport allowing check valve 22 to the directional valve 13 and finally third also directly to the directional valve 13. In line 14, a check valve 23 is switched on, which only allows a flow to the container 15 at a certain pressure in line 14, and a filter 24.

The directional valve 13, which consist of a hydraulically operated valve can has a middle layer, which is a neutral layer and is shown in FIG. 1. In this lase and the lines 11V and 11H through a central valve section 13N mutually connected, while the pressure side of the pump 16 through line 19 and return line 14 communicates with the oil tank 15.

The oil pumped by puape 16 thus goes to container 15 back while motor 10 can freewheel by keeping the oil in a closed loop Circle through the lines UV and 11H via the valve section 13N is conveyed. When moving the directional valve 13 to the right, section 13V changes to the hydraulic Systom switched on, which means that line 11V with the pressure line 19 of the Pump 16 is connected, while line 1111 is connected to return line via valve section 13V 14 comes into connection, where line 11V is the supply line of the motor 10 and line 1111 represents the derivative of the motor. If, on the other hand, valve 13 is turned to the left, so its valve portion 13H is turned on in the hydraulic system, where Line 11H with pressure line 19 of pump 16 and line 11V with return line 14 is connected so that line 11H is the feed line of the hydraulic motor 10 and Line 11V is its derivation. Both in the left and right position of the directional valve 13, the connection between line 19 and return line 14 is interrupted, as well the direct mutual connection between lines 11V and IIH. So far the design of the hydraulic system is by and large conventional. That New is that in lines 11V and 11H the two valve devices Special design 12V and 12II are switched on.

The valve devices 12V and 12H are identical, and the following Description of the 12V valve device also applies to the 12H valve device, in which the individual parts are, however, denoted with the suffix 11 instead of V.

The valve device 12V includes a 25V throttle valve, one with this in parallel it is coupled check valve 26V, which controls the flow of oil past the throttle valve in the direction of the hydraulic rotor 10, as well as one on line 11V on the Output side do3 throttle valve 25V and the check valve 26V connected Connection line 27V, which runs between line L1V and return line 14 and includes a check valve 28v that controls the flow from return line 14 to line 11V allows, but not in the opposite direction. The throttle valve 25V is loaded by means of a 29V spring towards the throttled or closed position, but there is a line from line 11V on the output side of the throttle valve 25V 30V branched off to transfer pressure to the outlet side of the throttle valve on an actuating device such as a piston or the like, which in opposite Direction to spring 29V works, so that the throttle valve 25V from pressure on its Exit side is led in to the open position. A corresponding actuator direction to act on throttle valve 25V in the same direction as that in the field 29V acts, but also belongs to the throttle valve 25V, and this actuator is connected to a line 31V which is connected to a brake valve 32, which belongs to a hydraulic auxiliary power system. This brake valve is for example can be changed by a pedal 33 arranged as a switching element, from a neutral position, in which through valve 32 a connection between line 31V and the corresponding one Line 31H for valve device 12H on the one hand and a line 34, which via a Filter 35 is connected to an oil tank 36, on the other hand brought about is. An auxiliary power pump 37 is connected to its suction line 38 via a filter 39 Oil tank 36 connected, while its pressure line 40 via a conventional one Overflow circuit 41 with overflow valve 42 via filter 35 with oil tank 36 and is connected to brake valve 32 by a line 43. By switching dos brake valve 32 by means of pedal 33 can dis both throttle valves 25V and 25H against the pressure that is exerted in line 30V or 30H, to more or less strong throttling. Boi Neutrallago des Bremsventil3 32 consists Connection between the Ful lines 31V and 3111 of the throttle valves 25V uiid 251-1 connected hydraulic control devices so that the oil in these to the Reservoir 36 may decline when the throttle valves are depressurized in the lines 30V and to be switched to the open position.

Lines 44Y and 44H only collect and discharge leakage oil from the throttle valves 25V and 25H are connected to a tank 45V and 45H, respectively. In practical experience, the containers 15, 36 and 45 consist of one and the same Oil tank, Before explaining the function of the hydraulic system described in more detail a structural design of the valve devices 12V and 12H is to be included Referring to Fig. 2 will be described in detail.

Each valve device has a valve housing 50 which has a bore 51, which is connected to the part of the line 11V or 11H, which is from the valve device goes to the hydraulic motor 10, and a bore 52, the is connected to the part of the line 11V or 11H which leads to the directional valve 13, There is a kickback between these two holes.

valve 26V or, H attached, in one of two to each other angled bores 53 and 54 formed internal connection in the valve housing 10.

An extension of the bore 54 forms line 27V or H, and thereon the check valve 28V or 11 is connected, which consists of a standard check valve may exist that allow a disturbance in the bore 54 in the housing 30 and should be connected to line 14. Between the bore 52 and the bore 51 the throttle valve 25V bsw, K is mounted in a bore 55, and it has one Connection 56 for line 31V or H. This should be completely clear as the valve device according to FIG. 2 according to FIG. 1 installed in the hydraulic system since should. A more detailed description of the structural design of the both Valves 25 and 26 should now follow.

Valve 25 has a valve body 57 which has a fixed seat 58 in bore 55 in housing 50 for the purpose of controlling the connection between the bores 51 and 52 cooperate through hole 55. The valve body 57 is as one piece formed with piston 59 and is loaded by a compression spring 60, the spring 29V or, H in Fig. 1 corresponds to and between the piston 59 and formed as a barrel an abutment 61 fastened in bore 55 is clamped around the valve body 57 to load the seat 58, between the two sides of the piston 59 is a Connecting channel 62 arranged.

In the abutment 61 there is a bore 63 and the connection through this bore is controlled by a valve cone 64, which is controlled by a compression spring 65 is held in the closed position between the valve cone and a piston 66 is clamped, which is guided in a nipple 67 which is screwed into bore 55 and forms the connection 56, through which a hydraulic pressure in line 31V or H to increase the pressure of the spring 66 to the valve cone 64 for action can be brought to piston 66.

Abutment 61 and nipple 67 are made in one piece and have a transverse bore 68 connected to line 44 for draining off leakage oil which passes through the bore 63 on the valve cone 64.

The check valve 26V or, H consists of a piston 70 with a valve body 71 thus manufactured in one piece, which is connected to one of the mouth the bore 55 formed seat 72 cooperates. Valve body 71 is of a Compression spring 73 pressed against this seat, which is between piston 70 and one in the housing screwed plug 74 is clamped.

It should be assumed that the directional valve 13 is acted, so that valve section 13V in the hydraulic. System switched on will.

Pump 16 then releases oil under pressure to line 11V, which in this case Adjustment of the directional valve acts as the inflow line of the motor while line 11H the drain line of the engine and through valve section 13V with container 15 is pre-tied. The connection between pressure line 19 of the pump and return line 14 is interrupted in valve section 13V. The oil supplied by the pump 16 flows from line 19 via check valve 22 and valve section 13V to line 11V and passes the throttle valve 25V, which is throttled by spring 29V or closed position is held by the check valve 26V, to then through the remaining part of the line 11V to get to the motor 10 and drive it. As can be seen, the oil cannot come through line 27V to line 14, as this is prevented by the check valve 28V.

In the drain line 11H of the motor 10, the oil flows from the motor to the valve device 12H, where the oil via line 30H the throttle valve 2511 against the effect of the Brings the spring to the open position while the oil is not on the check valves 26H and 28H can get past. Recalling E'ig. 2 the oil flows from the engine through line 11H to bore 51 and from there 4 through 13 bore 30H to pass through channel 62 to get behind piston 59, and from there to flow through channel 63 to column 68, from where the oil is diverted through line 44H to tank 45H. Here is Valve body 57, against the action of spring 60, lifted from seat 58. From the throttle valve 25H follows the oil via valve section 13V, check valve 23 and filter 24 Container 13 back.

If the engine is now to be decelerated, the directional valve 13 preferably initially brought into its neutral position, valve section 13N in the hydraulic system is switched on. By the action of pedal 33 this becomes 01, which is conveyed from pump 37 through lines 40 and 43 to valve 32, brought about through line 31H, but also through line 31V, to the respective Throttle valves 25H and 25V act. Here these valves are used for throttling brought. The fact that the valve throttles 25V is meaningless for the function of the system, while the throttling of valve 25H causes motor 10 to be braked, because he then has to work against the counterpressure brought about by the throttling will. By depressing the pedal 33 ever more forcefully, one can become stronger and stronger increasing throttling and thus braking can be achieved. Because of the pressure in the pipe 31H acts on piston 66 so that valve cone 64 is harder after its seat is pressed in bore 63 in abutment 61. The more heavily the valve cone 64 is loaded the less oil can get to container 45 in this way, which means that spring 60 holds the valve body 57 closer and closer to the seat, with increasingly stronger resulting throttling. Releases the pressure on valve cone 64 by decreasing of the pedal 33 after, the oil flow increases after gap 68, so that valve body 57 is pressed from its seat, which has a decreasing throttling result.

The braking device according to the invention thus gives the machinist the possibility of installing the directional valve in one or the other operating position 13V or 1311 set to operate the motor 10 in one direction or the other and then around the motor - which is extremely important - by adjusting the directional valve iu central lo or neutral position 13N to let go in freewheel, with the capacity the hydraulic Pump 16 for operating other hydraulic drives parts can be exploited while pressing pedal 33 on the engine a stronger or weaker braking force is exerted. The invention thus remedies The disadvantages mentioned in the introduction are such that the machinist can no longer act complete freedom is given to the bromine process.

When braking suddenly, there may be 11V in line due to leakage There is a large negative pressure in the engine, and this can cause pump 16 the supply in the neutral position of the directional valve 13 via valve 22 cannot be maintained but the oil is carried along the way where the resistance is least is, namely through valve section 13N and return line 14 to container 15. Thus the oil can still flow to the suction side of the engine, there is a connection through line 27V (27H) via check valve 28V (28H).

The check valve 28V (28H) is so loaded that it is after check valve 23 opens if there is no negative pressure in line 11V (11H). However, it comes to that such a negative pressure, valve 28V opens.

Braking can also take place at every end position of the directional valve, pump 16 counteracting a counter pressure which can then be so strong that the overflow valve 21 opens.

In Fig. 3 there is shown a small practical part of the valve device shown, which is very important for the function of the valve assembly. On valve cone 64 a disk 69 los + is attached, and thanks to this disk an otherwise Occurring oscillation of valve cone 64 prevented. This is because that the oil passing through channel 63 is deflected to the side by the disc and thereby a hydrodynamic one Pressure force on valve cone 64 triggers, which is added to the static pressure acting on it.

The disk can be replaced by a corresponding shape on the valve cone 64 will.

Claims (8)

Patent claims 1. Braking device on a reversible hydraulic motor (10), which is coupled to a load with great inertia and inflow and outflow lines (1lV, 11H) for hydraulic fluid and one connected to the lines Main control valve (13) for directing the flow of hydraulic fluid to the Drive the motor in one or the other direction and to activate the The motor has a short circuit in the cables, which means that it is not possible to use it n e t that in each of the lines (11V, llH) a means of one from the machinist Any common switching element (33) to be actuated to control the throttling effect adjustable throttle valve (25V, 25H) is attached in the short circuit and a with this check valve (26V, 26H) connected in parallel, which controls the flow of the hydraulic fluid allowed in the inlet direction. 2. Braking device according to claim 1, d a d u r c h g o k e n n notices that the throttle valve (25V, 25H) is spring-loaded for the throttle position (29V, 29H) and equipped with a hydraulic actuator (30V, 30H) connected to the side of the throttle valve used to control the Throttle valve for the open position, against the effect of the spring load, with motor (10) is connected. 3. Braking device according to claim 2, d a d u r c h g e k e n n note that the throttle valve Qine hydraulic actuator (32, 31V, 31H) for actuating the throttle valve to the throttled position. 4. Braking device according to claim 3, d a d u r c h g e k @ n n note that the throttle valve (25 ?, 25H) a throttle valve part (57) with an actuating piston (59) slidably guided in a bore (55) has, between the two sides of which a connecting channel (62) is arranged, wherein one side of the actuating piston to the line between the throttle valve and The motor is connected, while the other side is connected by a connection (63), by means of a throttle part which can be set by actuating the switching element (33) (64) is connected to a drain (44Vy 44H). 5. Braking device according to claim 4, d a d u r c h g e k e n n z e i c h n e t that the throttle part (64) is to be energized by the switching element (33) Load spring (65) is loaded to the throttling position. 6. Braking device according to claim 5, d a d u r c h g e k e n n z e i c h n e t that for the loading spring (65) one by hydraulic pressure movable spring support (66) controllable by the switching element (33) is attached, 7. Braking device according to claim 6, d a d u r c h g e k e n n n z e i C h n e t that on the throttling part (64) an extension (69) facing the connecting channel (63) is arranged. 8. Braking device according to one of claims 1-7, d a d u r c h it is not noted that on each line (11V, 11H) there is a non-return valve regulated inflow (27V, 27H) for the transport of oil to the line (11H) negative pressure occurring therein. L e r s e i t e