DE2425680A1 - AUTOMATIC LOAD OR TORQUE CONTROL FOR VEHICLES AND EQUIPMENT FOR IT - Google Patents

Description

• W-ta «. H. INCLUDING Wpl.-lns. K. GUNSCHUANH

• r. nt. nat W. KORBES __ “. _xrvr7 .

Hm-In ^ j. sch μ ι OT-evens May 28, 1974 I MUNICH 22. SUiMdMitr. M. Technion Research

and Development Foundation Ltd.

Senate House, Technion City

32 OOP Haifa / Israel

Patent application

Automatic load or torque control for motor vehicles and 'equipment for it · "'

The invention relates to an automatic load or Torque control for motor vehicles and the like, that are driven via a (transmission) gearbox, such as road vehicles, tractors, road construction machines, Earth moving equipment and the like.

In the following the term "hydraulic clutch" is used both for torque converters as well as for hydraulic clutches used as they are in automatic transmission or power transmission units be used.

The efficiency of an automatic power transmission unit with a torque converter or with a hydraulic clutch as a connecting link between an engine, in particular an internal combustion engine, and the mechanical transmission is im essentially dependent on the slip between the driving part and the driven part of the clutch. These power transmissions are therefore designed for automatic gear change in order not to overload the engine and not to

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(coincidentally) the torque on the hydraulic clutch over to increase the range of optimal efficiency. Gear change is achieved through a combination effect the revolutions of the shaft that drives an oil pump on the one hand and the throttle or throttle opening on the other. The resulting oil pressure becomes a changeover control valve SngepaiBt or supplied, through which the opening or closing the clutches and brake bands of the adapted associated Planetary gear takes place. It can be seen that improper load adjustment can either result in the slippage of the hydraulic Coupling enlarged, which leads to energy losses and thus excessive egg heating, or too large transmission ratio can result while the torque is low and the slip of the hydraulic clutch is small is.

A control of the (transmission) gearbox by two combined Factors of output shaft speed and throttle opening is complicated and, under under certain circumstances, unsatisfactory in terms of engine torque. In addition, it is relatively complex.

It is an object of the present invention to provide an automatic load or torque control for motor vehicles and the like, which do not have the above-mentioned disadvantages. This task is performed by a like in the The preamble of claim 1 outlined control is solved, which is characterized according to the invention, as in the characterizing part of claim 1 is specified. Further refinements and developments of the invention emerge from the subclaims emerged.

In the present invention, the proportional slip of the parts of the hydraulic clutch is used to set the gear steps of the transmission, i.e. the transmission ratio of the mechanical transmission, to change or switch over, in

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Respecting constant torque at optimal speeds of the engine. In a similar way, it can reduce the load caused by the resistance of the soil in earthmoving machines or the like can be changed by hydraulically raising or lowering the shovel, ripper, des Slide. Or the respective tool, which over or against the ground is moved when the slip is too high or too low.

The invention consists in an automatic load control for a road vehicle, tracked vehicle, or any other powered machine which has a hydraulic coupling ^ ment or a torque converter as a connecting link between the engine and the mechanical transmission. In the Invention, the revolutions of the driving part and the driven part of the hydraulic clutch are the input a measuring device for the slip supplied, which thereupon an electrical output signal for switching on a lower Gives off gear when the proportional slip has reached a predetermined high value, and an output signal gives off for switching on a higher gear, if the proportional slip has always reached a predetermined low value. For earthmoving machines, the output signal can be the measuring device for the slip can be used to determine the load or workload on the machine associated work tool acts to reduce, namely by the fact that it is lifted from the ground, its angle of attack changed or something similar is done.

In a preferred embodiment of the invention are • two rotating parts provided, one with the driving and the other is connected to the driven side of the hydraulic clutch. This "connection is either directly or via a mechanical transmission. It is made with units that are magnetic or optical Send out impulses, provided at equal intervals from the

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Ren axis and evenly spaced from each other are. Two pulse counters are provided and arranged to receive pulses from each of the sides and an output a common logic circuit which is adapted to convert the pulses into electrical signals converts that at a given maximum and a given minimum proportional slip of the driven Side of the clutch. These signals are further at least one electro-hydraulic or electro-pneumatic control valve for switching the gear stage of the mechanical power transmission that is driven with the Coupling half is connected, or fed to change the position of the work tool of the machine.

The pulse-emitting units can consist of a plurality of bodies made of magnetic material such as iron, which are arranged at equal intervals and protruding around the circumference of a circular or cylindrical body and one of which is connected to the drive shaft and the other to the output shaft of the hydraulic clutch are. The pulses are generated by the fact that these bodies are exposed to the magnetic field of the magnetic recording device be moved therethrough, this device being provided in the vicinity of the body.

In another embodiment, the pulses are generated optically, with the mechanism consisting of a rotating body, the one number in regular intervals arranged columns or slots, which forms the circumference of this body with holes. Next includes this Mechanics a light source and a light sensor on opposite sides of the parts provided with soldering of the rotating body is arranged in such a way that the light emitted by the source always reaches the sensor if a gap or a slit denotes. Light path crosses.

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Further explanations of the invention can be found in the description of the exemplary embodiments shown in the figures and show it:

1 shows a schematic side view of a control device with a magnetic pulse measuring device for slip,

2 shows a torque converter with an optically working Measuring device and an electronic gear step control device ..

Fig.1 shows a hydraulic clutch 1, which is from an input- or a drive shaft 11 which is fixedly connected to a drive torus 12 is driven. This torus 12 has radial blades or vanes within the clutch housing. The flow of the rotating resp. circulating oil gives a similarly specified torus 13 a torque with the same sense of direction, however at a lower speed or rotational speed than the drive shaft has. The torque of the driven torus is based on a mechanical gear or a planetary gear arrangement 2 transmitted via the output or output shaft 14.

As is easy to see, this output shaft rotates at a lower speed or rotational speed than the drive shaft. The quotient, formed from the difference between the speeds or speeds, divided by the drive speed or speed is referred to as the "proportional slip" of the clutch. This slip s = (nO ~ n1) / nO or that Speed ratio r = n1 / nO should be kept within certain limits in accordance with the design of the fluid coupling. In this way you can Avoid high friction losses and excessive heating of the hydraulic fluid. It's the job of the mechanical (Transmission) gearbox 2, an overload of the Clutch and the machine by ensuring that a suitable

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sendes ratio of the speed n1 of the clutch output shaft and the speed n2 of the (gear) drive shaft 21, which is located at the rear end of the transmission and from which the power is transmitted to the vehicle wheels v.-ird, provided or set will.

As mentioned above, automatic transmissions are used in known automatic transmissions the gear steps are switched by means of oil pressure, which is determined by the factors linked to the throttle or throttle lever position and the vehicle speed in terms of speed n2 is obtained. In the present embodiment according to the invention is the relative slip of the clutch output shaft to do this, an automatic gear change as follows to set in motion. There are two matching gear wheels or wheels 31 and 32 which are otherwise provided with teeth made of a steel alloy, which have a matching number of 33 teeth. The wheel 31 is on the drive shaft 11 and the red 32 firmly attached to the output shaft 14 and they rotate along with these waves. The teeth 33 opposite are at a close distance from each Wheel two magnetic recording devices 34 and 35, whose magnetic field is interrupted by each of the passing teeth, resulting in an electrical impulse at a time leads. These pulses are then fed to two counters 36 and 37 which are adapted to receive their output signals a logic circuit 35 feed. This rice 33 is programmed to send commands to an electromagnet 39 of a pneumatic or hydraulic control valve transmits, depending on certain low and high Points or values of the calculated slip (nO-n1) / nO. In order to or thereby the gear stage of the mechanical transmission is switched to a higher or a lower gear stage, whereby a desired clutch slip is obtained and the engine power is controlled. The connection between the control valve 39 and the transmission 2 is represented by the three lines 22. For transmissions with a larger number of gear

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stages, even more lines are required.

Instead of calculating the slip (nO-ni) nO, the electronic Means be designed to match that they work with the speed ratio r = n1 / nO, "where a

fixed value "nO" is given and the second speed "n1" is variable. The load or torque change is carried out accordingly. This is achieved by having the pulse counter 36 on the motor side emit a signal every time a fixed number of "No" pulses, for example 1000 pulses, has been received During this, the number of pulses "N1" is counted by the second counter 37 and sent to the logic circuit. The number N1 indicates the speed ratio If, for example, the number of pulses that have been counted by the counter 37 is at a point in time N1 = 950, this point in time being determined by the count "1000 pulses" of the counter 36, this would be a speed ratio of 0.95 or correspond to 5% slip. for example, if the limits for the range of the slip, 6% and 2%, corresponding to a speed ratio of 0.94 and 0.98, w A command to switch to a lower gear is given with 940 pulses and a command to switch to a higher gear is given with 980 pulses. It can be seen that the number 1000 is chosen arbitrarily and that any other number can be chosen which takes into account the number of teeth and the number of revolutions of the motor.

Fig.2 shows a similar embodiment, but with one Torque converter 1 ', a known embodiment, the is put in place of the hydraulic clutch. This torque converter consists of a pump 12 connected to the drive shaft 11 is connected, which passes through the converter housing. It also consists of a stator 15 and

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a turbine 13 which is connected to the output shaft 14. The slip of the turbine 13 with respect to the pump 12 is measured and used to control the mechanical (transmission) transmission by means of the following arrangement. It two parallel disks 32 'and 31' are provided, of which one is firmly connected to the output shaft 14 and the other to the pump housing 12. They run accordingly at different speeds or rotational speeds, according to the slip of the driven turbine. Both discs are provided or perforated near their outer edge with an equal number of radially directed narrow slots 33 ', which are at the same distance from each other and are on the same diameter. It is a light source 5, e.g. small light bulb, is provided, which is located between the two discs on the radius or diameter of the slots 33 '. Two light sensors 34 'and 35' are located on the respective outside of the panes opposite the light source. These are designed and arranged so that they through absorb light passing through the slits as they pass through.

The alternation of darkness and light recorded by the sensors gives a large number of pulses to be expressed by No = ηθ · ζ, N1 = η1 · ζ, where ζ is the number indicating the slots in each disc. These pulses are transmitted to two counters 36 and 37, the signals on output a logic circuit 38. The latter serves the purpose the necessary commands to an electromagnet 39 of an electro-hydraulic or to deliver electro-pneumatic control valve 40, which controls the gear steps or shift of the mechanical Transmission 2 shifts.

In connection with this embodiment it should be pointed out that a torque converter is designed: a \ for e «hr much larger area of slip than with a hydraulic clutch; b \ for a ratio of the pump speed or speed to turbine speed at maximum efficiency

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different from 1: 1, depending on the curvature and the angles of the blades »Accordingly, the converter can be suitable for setting the limit values between the lowest value of the slip s 20% and the highest value of the slip = hO% , whereby the efficiency of the converter is satisfactory between these values.

This is in contrast to fluid couplings, in which a slip of 3% can be selected as the upper limit in order to avoid energy losses and to initiate a gear change.

In the case of earthmoving machines, the facility at Command given to the upper and lower limit value of the slip be transferred to a hydraulic mechanism, which is a ripper or ripper, a shovel or a similar tool raises or lowers, or the angle of attack of such Shovel changed.

The invention is not restricted to the two embodiments described above and many others can be used Refinements and modifications are made within the scope of the invention. E.g. instead of counting devices with magnetic and optical pulses any other known measuring device for slip can be used with the appropriate Output signal for sending the commands for changing the gear ratio in an automatic transmission can be obtained can.

Instead of. Gears, as shown in the electromagnetic embodiment, can be any other., Magnetic Rotating bodies emitting pulses can be provided, e.g. a disk made of non-conductive material such as plastic material, are inserted into the strips of iron in or on the periphery of the same.

The number of pulse-emitting units depends on the number of revolutions of the hydraulic clutch and for

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very high rotational speeds, it can be useful only one or two impulse-emitting points on the circumference to be provided.

The pulse-emitting rotating bodies can be attached to any part of the hydraulic coupling, provided that the proportional slip can be measured. For example, it may be appropriate to use a magnetically operating transducer facing the teeth of the starter ring on the engine flywheel and a second wheel on any one To attach part of the device that runs at a speed of rotation that of the turbine wheel is adapted. It is not necessary to have the same number of pulse-emitting units on both sides of the coupling provided, since the outputs of the pulse counters can be set or adapted accordingly.

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Claims (5)

Claims Automatic load or torque control for motor vehicles and the like, which have a hydraulic clutch or a torque converter between the engine and the drive wheels or chains, characterized in that the speed of the driving part (12) and that of the driven part (13 ) the hydraulic clutch (1) or the torque converter (1 ♦) are fed to the input of a measuring device (34 to 38), which is designed so that it is at a predetermined value of the slip of the clutch (1) or the converter (1 ¹ ) emits an electrical output signal to change the (torque) load on the motor, with this signal either switching on a different level of fine mechanical (overexcitation) gear or changing the load on a device attached to the vehicle. 2. Control according to claim 1, characterized in that that the signal at a predetermined high value of the slip of switching to a lower gear or causes a reduction in the load on the device on the vehicle. 3. Device for automatic control according to claim 1 or 2, characterized in that the device has two rotating bodies (31, 32, 31S 32 ·), one of which (31, 31 ') with the driving side (12) and the other body (32, 32 ¹ ) is connected directly or indirectly to the driven side (13) of the clutch (.1) or the transducer (1 ¹ ), each of these bodies having units (33 , 33 '), which are arranged on the same diameter in relation to the axis and at equal distances from one another, so that the device im- 409881/0344 having pulse sensors (34, 35> 35 ', 34') which are designed in this way are that they are able to absorb magnetic or optical impulses: and one of each of them? close ever one of the rotating bodies (31, 32, 31 ', 32') is en-ordered is that the device has pulse counters (36, 37) which are electrically connected to one of the sensors and so are arranged to give their output signals to a common logic circuit (3B) of the device, which calculates the proportional slip of the clutch or the converter and an electro-hydraulic command or electro-pneumatic device (39, 40) with when a predetermined, in particular high, value of the slip is reached by changing the automatic Power transmission and switching to another, especially lower, gear change the load, in particular is reduced, and vice versa. 4. Device according to claim 3, characterized that the two rotating bodies have the shape of disks (31, 32, 31 ', 32') or cylinders and one Number of pulse-emitting parts (33) made of magnetic material, e.g. iron, which are uniformly spaced along the Perimeter of the individual body (31, 32) are distributed, wherein these parts generate electromagnetic pulses when passed through the field of a magnetic pickup (35) run through them near them. 5. Device according to claim 3, characterized in that that each of the rotating body is designed as a disc (31 ', 32') or as a hollow cylinder and with a Number of equally spaced gaps or holes is provided in the circumference, and that a light source (5) and a light sensor (34, 35) are arranged on opposite sides of the gaps or holes (35 ') in such a way that Light emitted by the light source then reaches the respective sensor when a gap or hole passes through the light path crosses. 40988 1 / The patent attorney