GB1569638A

GB1569638A - Internal combustion engine

Info

Publication number: GB1569638A
Application number: GB15787/77A
Authority: GB
Original assignee: IHI Corp
Current assignee: IHI Corp
Priority date: 1976-04-16
Filing date: 1977-04-15
Publication date: 1980-06-18
Also published as: CH622315A5; FR2348369A1; IT1075326B; DE2716942A1; DK162277A; FR2348369B1

Abstract

The device has a hydraulic cylinder (10), which is controlled by a control valve (9) for opening and closing an inlet, exhaust, fuel injection or starting valve (11). The control valve (9) is in turn controlled by a computer unit (6) which calculates the optimum timing control for the valve (11) on the basis of an electrical signal representing the movement of the pistons or the crankshaft. The hydraulic control valve (9) can be driven by multi-layer piezo- electric actuators (12). As a result the internal combustion engine (1) can be of more compact construction, the mechanical loss can be reduced, the efficiency increased, the direction of rotation of the engine (1) easily changed and the noise emission considerably reduced. <IMAGE>

Description

(54) INTERNAL COMBUSTION ENGINE (71) We, ISHIKAWAJIMA-HARIMA JUKOGYO KABUSHIKI KAISHA, a Company organised under the laws of Japan, of No. 2-1, 2-chome, Ote-machi, Chiyoda-ku, Tokyo-to, Japan, do hereby declare the invention for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in any by the following invention.

In the past internal combustion engines have used cam driven mechanical valve mechanisms. They tend to be large and complex so that there are substantial mechanical losses, and much noise, and the engine cannot be rapidly reversed. In some engines, a common cam or cam shaft is used to drive not only a fuel pump for producing a high fuel injection pressure of the order of approximately 1,000 kg/cm2 but also a fuel injection timing control mechanism and an injection quantity control mechanism. The cam or cam shaft is in turn driven through large gears and chains so that adjustments (of the order of 10-2 to 10-lmm) of the timing and quantity control mechanisms and the engine output or combustion pressure within a cylinder may be accomplished only by skilled and experienced mechanics.

Furthermore, the adjusted parts tend to deviate due to the temperature variation, vibrations, abrasion and wear and elongation during the operation. The valve-timing is in general fixed regardless of the variation in load or speed and the valve-timing of fuel valves cannot be freely changed during the operation so that it is extremely difficult to always attain an optimum engine efficiency.

As a result, with these engines it is difficult to solve the pollution problem or to reduce the NOx content in the exhaust gases.

According to the invention an internal combustion engine has means arranged to give an electrical signal representative of the angle or speed of the crankshaft, and computing means which controls in response to that signal a piezo-electric transducer which operates an actuator arranged to operate an engine valve, a fuel injector or ignition means.

The invention may be carried into practice in various ways, and certain embodiments will be described by way of example with reference to the accompanying drawings, in which: Figure I is a block diagram of a device for controlling the operation of an internal combustion engine; Figure 2 is a longitudinal sectional view of a hydraulic control valve used in the device shown in Figure 1 Figure 3 is a block diagram of a second embodiment of the present invention; Figure 4 is a block diagram of an arithmetic control unit used in the second embodiment for controlling an exhaust valve.

Figure 5 is a block diagram of an arithmetic control unit used in the second embodiment for controlling a fuel injection valve; and Figure 6, is a longitudinal sectional view of a hydraulic control valve used in the second embodiment Referring to Figure 1, reference numeral 1 denotes an internal combustion engine; 2, a crankshaft angular-velocity sensor; 3, a converter for converting an angular velocity of the crankshaft into a rotational speed; 4, a forward or reverse instruction generator; 5, a parameter generator for generating a parameter used in the computation for determining a valve-timing; 6, an arithmetic unit; 7, a comparator; 8, an amplifier; 9, piezo-motor-driven hydraulic control valve; 10, a hydraulic cylinder; and 11, a valve.

In Figure 2 there is shown in detail the piezo-motor-driven control valve for controlling the hydraulic cylinder 10. It includes laminated piezoelectric transducers (finemotion actuators) 12 and 12' each consisting of a lamination of a positive electrode disk, a ceramic piezoelectric element disk, and a negative electrode disk vertically disposed in the order named so that in response to the on-off operation of the voltage applied across the transducer 12 or 12', the latter may be expanded or contracted in the directions indicated by a double-pointed arrow.

The control valve 9 has a housing consisting of three split valve casings 13, 19 and 20, and the laminated piezoelectric transducers 12 and 12' which will be referred to as "fine-motion actuators" in this specification for brevity are disposed within the upper valve casing 13 closed with a cover 14.

Pistons 15 and 16 or 15' and 16' are fitted into a piston guide 17 or 17' below the bottom of the fine motion actuator 12 or 12' in such a way that they may be liquid-tightly vertically slidable. Connected to the pistons 15 and 16 is the upper end of a valve rod 18 or 18' having an oil passage 27 extended coaxially thereof. The valve rod 18 or 18' extends through the intermediate valve casing 19 and terminates in the lower valve casing 20. A valve seat sleeve 21 or 21' which is interposed between the intermediate valve casing 19 and the valve rod 18 or 18' is normally biased downwardly by a spring 22 or 22'.

An oil passage 23 is communicated through an oil line 24 with a pressure source while an oil passage 23', through an oil line with a tank not shown), and an oil passage or port 25 is communicated with the hydraulic cylinder 10.

Next the mode of the first embodiment will be described. Referring back to Figure 1, the operating condition of the internal combustion engine 1 is detected in terms of the movement of pistons and hence the rotation of the crankshaft, which in turn is converted by the sensor 2 into an electrical signal. This signal is converted by the converter 3 into an electrical signal representative of a rotational speed of the crankshaft. This signal as well as the signals from the forward or reverse instruction generator 4 and parameter generator 5 are applied to the arithmetic unit 6 which executes an arithmetic operation based on the rotational speed of the internal combustion engine 1, the forward or reverse instruction and the parameter applied to determine an optimum valve-timing; that is, the angles at which the intake and exhaust valves are opened and closed.The output signal from the arithmetic unit 6 is applied to the comparator 7 where the output signal is compared with the output signal from the converter 2. The coincidence signal from the comparator 7 is applied to the amplifier 8 and the amplified signal is transmitted to the piezo-motordriven control valve 9.

Assume that a voltage be applied across the transducer or actuator 12 so that the piezoelectric element is expanded causing the pistons 15 and 16 to be shifted downward. Then the piston 16 causes the oil in a space 26 to flow through the oil passage 27 into a chamber 28 so that the valve seat sleeve 2 is forced to slide upwardly relative to the valve rod 18 against the spring 22 and consequently a valve port 29 which is defined by the valve rod 18 and the valve seat sleeve 21 is opened. As a consequence, the pressure source is communicated through the oil line 24, the oil passage 23 and the valve port 29 with the oil passage or port 25 and hence the hydraulic cylinder 10.

When the voltage applied across the actuator 12 is removed while the voltage is applied across the right actuator 12', the spring 22 pushes the valve sleeve 21, whereas the oil in a space 26' is forced into a chamber 28' so that the valve seat sleeve 21' is forced to slide upward relative to the valve rod 18', whereby a port 29' is opened.

As a result, the oil in the chamber 30' is forced to flow through an oil passage 31 into the chamber 30, thereby forcing the valve seat sleeve 21 to move downward. The oil in the chamber 28 is forced to flow through the oil passage 27 into the space 26 so that the valve rod 18 and the pistons 15 and 16 are lifted and the valve port 29 is closed. When the voltage is applied alternately across the actuator 12 and 12', the control valve functions as a three-position control valve which opens and closes its ports 29 and 29' at a very high speed.

Referring to Figure 3, reference numeral 41 denotes an internal combustion engine; 42, a crankshaft angular-velocity sensor or tachometer; 43, an arithmetic unit; 44, a piezomotor-driven hydraulic control valve; 45, a hydraulic cylinder driven by the control valve 44; and 46, a valve which may be a fuel injection valve, an intake valve, an exhaust valve or a starting valve.

The arithmetic unit 43 is shown in detail in Figures 4 and 5. The unit shown in Figure 4 is used for controlling an exhaust valve, an intake valve or starting valve whereas the unit 43 shown in Figure 5 is used for controlling a fuel injection valve.

First referring to Figure 4, the output signal from the sensor 42 is applied to a converter 47 to be converted into a signal representative of the rotational speed n of the engine. The output from the converter 47 is applied to first and second arithmetic units 48 and 49 each of which computes based on the rotational speed n and a parameter transmitted from a parameter generator 50 for generating a parameter used in the computation of a valve-timing, thereby obtaining a correction of the crankshaft angle at which the valve 46 (See Figure 3) is opened or closed.

More specifically, the arithmetic units 48 and 49 execute the operation of (+ an*b) where a and b are parameters generated by the parameter generator 50, and n is the rotational speed. The parameter generator 50 may consist of daisy switches or potentiometers so that the values of the parameters a and b as well as their senses may be easily changed as needs demand.

The output signals from the arithmetic units 48 and 49 are applied to first and second adders 51 and 52 to which is also applied the output signal from a reference valve-timing generator 53, representing a reference valve-timing or the angle at which the valve 46 is opened or closed. Therefore the output signal from the generator 53 is predetermined depending upon the type of valve 46 and depending upon whether this valve 46 is opened or closed. The adder 51 or 52 adds the output signals from the arithmetic unit 48 and 49 and the reference valve-timing generator 53 and the sum is checked by a limiter 54 or 55 so as not to exceed a predetermined value.

A first comparator 56 receives the output y from the sensor 42 and the output a from the first limiter 51 and transmits the output of an amplifier when and only when y 3 a to drive the control valve 44 to open the valve 46. In like manner a second comparator 57 receives the output y from the sensor 42 and the output p from the second limiter 55 and outputs the signal to the amplifier 58 to drive the control valve 44 to close the valve 46 when and only when Y > P The arithmetic control unit 43 shown in Figure 5 is substantially similar to that shown in Figure 4 except that this unit is used exclusively for controlling a fuel injection valve.That is, only one arithmetic unit 48 is provided and the output signal from a governor 59 representing an injection quantity is applied to the arithmetic unit 48 and the second limiter 55 through a constant multiplier 60. That is, the output from the governor 59 is multiplied by k in the constant multiplier 60 to determine an angle of crankshaft rotation through which the fuel injection valve must be kept opened.

The output representative of a reference valve closing angle from the generator 53 is not applied to the second adder 52 as with the arithmetic control unit shown in Figure 4, and only the output a from the limiter 54 is applied thereto.

The arithmetic unit 48 executes the operation of ( :::: c n f dy + e ) where c, and e are derived from the parameter generator 50; n, the rotational speed of the engine; and y, the injection quantity signal from the governor 59.

In Figure 6 there is shown in detail the hydraulic control valve 44 used in the second embodiment. It has a housing consisting of three split casings 62, 70 and 84 and two fine motion actuators 61 and 61' substantially similar in construction to those 12 and 12' shown in Figure 2. The fine motion actuators 61 and 61' are disposed within the upper valve casing 62 covered with covers 63 and 63' and are expanded or contracted in the directions indicated by the double-point arrows when the voltage is applied. The covers 63 and 63' are adapted to absorb the reactions from the actuators 61 and 61'.

A large-diameter piston 64 or 64' is slidably fitted into a cylinder block 64 or 64' which in turn is fitted into the intermediate valve casing 70 and is securely held in position by a distance piece 65 and 65'. The large diameter piston 64 or 64' has its upper end in contact with the bottom of the actuator 61 or 61'. Another cylinder block 67 or 67' is fitted below the cylinder block 66 or 66' to define a space 68 or 68' in which is trapped oil. A small-diameter piston 69 or 69' is slidably fitted into the cylinder block 67 or 67' and has a nonreturn valve for preventing the leakage of the oil from the space 68 or 68'. The nonreturn valve consists of a ball valve 71 or 71' which is biased by a spring 72 or 72' having its upper end received by a nut 73 or 73' formed with a passage in communication with the space 68 or 68'.A vertical passage at the lower end of the nonreturn valve communicates with a horizontal oil passage 74 or 74' extended through the cylinder block 67 or 67' so that when the oil in the space 68 should leak, it may be supplemented from the exterior.

The lower end of the small diameter piston 69 or 69' is extended slightly beyond the lower end of the cylinder block 67 or 67' and is made into contact with the upper end of a poppet 75 slidably fitted into the lower valve casing 70.

The poppet or valve main body 75 or 75' consists of an upper cylindrical section, an intermediate tapered or inverted frustoconical section and a lower cylindrical section.

The upper and lower cylindrical sections slide in the cylinder wall and a contacting or seat face 76 or 76' in the form of a hook in cross section is formed between the tapered and lower cylindrical sections for contact with a valve seat 80 or 80'. A bias spring 83 is loaded in a blind hole formed in the lower cylindrical section of the valve main body 75 or 75' so that when the actuator 61 or 61' is turned off, it causes the valve main body 75 to move upwardly and consequently the contact or seat face 76 or 76' may be firmly pressed against the valve seat 80 or 80'.

Oil passages 77 or 77' and 78 or 78' are formed around the valve main body 75 or 75' and the valve seat member 79 or 79' is disposed within the upper oil passage 77 so that the valve seat 80 or 80' at the lower end makes contact wih the contact or seat surface 76 or 76' of the valve main body 75 or 75'. The oil passage 77 communicates through an oil passage 88 with a pressure source (not shown), whereas the oil passage 78 communicates through an oil passage 81 with the hydraulic cylinder 45 (See Figure 3). In like manner, the oil passage 77' communicate with an oil passage 88', whereas the oil passage 78' communicate through the oil passage 71 with the hydraulic cylinder 45.

A frustoconical guide 82 or 82' is fitted into the intermediate valve casing 70 to guide the lower cylindrical section of the valve body 75 or 75'. The lower end surface of the lower casing 84 is recessed to define a space 87 or 87' between the lower casing 84 and a bottom plate. The space 87 or 87' communicate through a hole 86 or 86' extending through the lower casing 84 and a hole 85 or 85' extending through the valve guide 82 or 82' with the oil passage 78 or 78'. Therefore the oil under pressure in the space 87 or 87' forces the valve guide 82 or 82' upwardly so that the axis of the valve body 75 or 75' may be correctly maintained.

Next the mode of operation will be described. Referring back to Figure 3. the angular position of the crankshaft of the internal combustion engine 41 is detected by the sensor 42 and converted into an electrical signal. The output from the sensor 42 is applied to the arithmetic control unit 43 of the type shown in Figure 4 or 5. First the mode of operation of the arithmetic control unit 43 shown in Figure 4 will described.

The output from the sensor 42 is apoplied to the converter 47 to be converted into a signal representative of the rotational speed N of the engine. The output from the converter 47 is then applied to the first and second arithmetic units 48 and 49 to which are also applied the outputs or parameters from the parameter generator 50. The first and second arithmetic units 48 and 49 execute the operations ( +a n + b ), and their outputs are fed to the first and second adders 51 and 52.

The first adder 51 adds the output from the first arithmetic unit 48 to the output from the reference signal generator 53 representing the reference valve opening angle, while the second adder 52 adds the output from the second arithmetic unit 49 to the output from the reference generator 53 representing the reference valve closing angle. These reference valve opening and closing angle signals are predetermined depending upon the type of valve controlled.

The outputs from the first and second adders 51 and 52 are transmitted to the first and second limiters 54 and 55, respectively, which prevent the outputs from the first and seconds adders 51 and 52 from exceeding a predetermined value. The output a from the first limiter 54 is applied to the first comparator 56 to be compared with the output y from the sensor 42 and is permitted to be transmitted to the amplifier 58 when and only when y > a so that the amplified output is transmitted to the control valve 44 to open the valve 46.

The output p from the second limiter 55 is transmitted to the second comparator 57 to be compared with the output y from the sensor 42 and is permitted to be transmitted to the amplifier 58 as the OFF signal when and only when o > p so that the amplified output is transmitted to the control valve 44 to close the valve 46.

When the output signal a from the first comparator 56 for opening the valve 46 is transmitted to the hydraulic control valve 44, a voltage is impressed across the first actuator 61 so that the latter is expanded downwardly by a distance proportional to the applied voltage and consequently the large-diameter piston 64 is moved downwardly, pressurising the oil in the space 68.

Then the large-diameter piston 64 in turn causes the small-diameter piston 69 to move downward. The downward stroke or displacement of the small-diameter piston 69 is considerably greater than that of the largediameter piston 64 because the former is equal to the downward stroke of the largediameter piston 64 multiplied by a quotient obtained by dividing the effective sectional area of the piston 64 by that of the piston 69 if the oil leakage is negligible.

The downward stroke of the smalldiameter piston 69 causes the downward movement of the valve body 85 against the spring 83 so that the contact face 76 of the valve body 85 is spaced apart from the valve seat 75 to communicate between the oil chambers or passages 77 and 78.

As a result, the working oil under pressure flows from the pressure source through the oil passages 88, 77, 78 and 81 into the hydraulic cylinder 45 (See Figure 3) to open the valve 46.

In response to the output ss or valve closing signal transmitted from the second comparator 56 through the amplifier 58, the voltage impressed across the first actuator 61 is removed while a voltage is impressed across the second actuator 61'. The valve body 75, and the small- and large-diameter pistons 69 and 64 are moved upwardly to their initial positions under the force of the biase spring 83, and the contact face 76 is firmly pressed against the valve seat 80 to interrupt the communication between the oil passages 77 and 78. On the other hand, the large- and small-diameter pistons 64' and 69' and the valve body 75' are forced to move downward in the manner described above so that the contact face 76' is spaced apart from the valve seat 80' and the communication between the oil passages 77' and 78' is established.As a result, the working oil returns from the hydraulic cylinder 45 through the oil passages 81, 78', 77' and 88' to the tank or sump so that the valve 46 is closed.

Since the hydraulic cylinder 45 is controlled by the hydraulic control valve 44 which in turn is controlled by the actuators 61 and 61', optimum combustion may be ensured in the internal combustion engine 41 over a range of operating conditions.

Sometimes the rotation of the internal combustion engine must be reversed. In this case, in response to the forward or reverse instruction generator (not shown), the first and second arithmetic units 48 and 49, the reference valve opening and closing signal generator 54, the first and second limiters 54 and 55 and the first and second comparators 56 and 57 all change their outputs. That is, the first and second arithmetic units 48 and 49 change the polarity or sign of the result; the generator 54 outputs the reference signals different from those in case of the forward operation; the first and second limiters 54 and 55 change their threshold values, and the first and second comparators 56 and 57 change their comparison conditions. Thus with only one arithmetic control unit an optimum valve-timing may be attained even in the reverse operation.

Next the mode of operation of the arithmetic control unit 43 of the type shown in Figure 5 will be described. As described before, this unit is used for controlling a fuel injection valve, and to this end the valve opening timing is determined in response to the result or output from the arithmetic unit 48, whereas the valve closing timing is response to the injection quantity signal from the governor 59. More particularly, in the unit shown in Figure 5 the valve closing timing is determined by adding to the valve opening timing a time in proportion to an injection quantity.The ON and OFF signals are transmitted through the control valve 44 described in detail above with reference to Figure 6, and the mode of operation through the arithmetic control unit 43 shown in Figure 5 is substantially similar to that described above in conjunction with the arithmetic control unit shown in Figure 4.

It is to be understood that the present invention is not limited to the preferred embodiments descibed above and that many modifications may be effected as will be described below.

1) In the first embodiment, the control valve of the type shown in Figure 6 may be used. In like manner, in the second embodiment the control valve of the type shown in Figure 2 may be used.

2) In the arithmetic control unit of the type shown in Figure 4, the valve opening and closing angle corrections are obtained from an equation of first degree with variables being the rotational speed of the engine and the injection quantity, but an equation of second degree with the same variables or any other suitable equations may be used.

3) In the arithmetic control unit shown in Figure 4, instead of the arithmetic units, the parameter generator and the reference signal generator, a function generator may be used which generates a suitable mathematical function between the variables and the valve opening and closing corrections. In like manner, the functional relationship between the variables and the valve opening and closing corrections may be programmed and stored in a memory in the arithmetic unit so that the corrections may be immediately obtained in response to the variables detected.

4) In the arithmetic control unit shown in Figure 4, in addition to the rotational speed of the engine and the injection quantity, the load, the injection rate, the intake air pressure, the intake air temperature and so on may be used as variables.

5) In the arithmetic control unit shown in Figure 5, the injection quantity or rate of injection, or the rotational speed may be eliminated.

6) In the arithmetic control unit shown in Figure 5, the load, the intake air pressure and temperature and so on may be used as variables.

7) In the arithmetic control unit shown in Figure 4 either of the first or second adder and of the first or second limiter may be eliminated. Alternatively all of them may be eliminated.

8) In like manner, either or both of the first and second adders and the first and second limiters may be eliminated in the unit shown in Figure 5.

9) In the arithmetic control unit shown in Figure 4, the arithmetic unit 48, the adder 51 and the limiter 54 and the second arithmetic unit 49, adder 52 and limiter 55 may be connected in any suitable order.

10) In the unit shown in Figure 5, the arithmetic unit 48, the adder 51 and the limiter 54 and the arithmetic unit 52 and the limiter 55 may be connected in any suitable manner.

11) In stead of the sensor 42 and the converter 41, any suitable tachometer such as a tachogenerator may be used for the detection of the rotational speed of the engine.

12) The limiter 55 in the arithmetic control unit shown in Figure 5 serves to control a maximum injection quantity so that it may consist of a potentiometer or daisy switch by which a driver or operator may easily change a setting value. Alternatively, it may be an automatic device of the type capable of changing a setting value based on a predetermined function such as K1 n2 + K2, where K1 and K2 are constants and n, is the rotational speed of the engine.

13) The valve opening and closing angles or timings may be determined manually.

The novel features and advantages of the present invention may be summarized as follows: (I) Complex cam shaft driving mechanism and valve mechanism-eliminated so that an internal combustion engine may be compact in size with low mechanical losses and high engine efficiency.

(II) Opposed to the conventional internal combustion engines, no skilled and experienced mechanic is required for the engine adjustments such as the engine output, the combustion pressure, the cylinder output balance, the exhaust gas temperature and so on. As a result, the engine may be operated with an optimum efficiency and a number of re-adjustments may be considerably reduced.

(III) The engine may be easily reversed in rotation.

(IV) The valve-timing may be automatically and optimumly changed depending upon the load or rotational speed. In an internal combustion engine of the type wherein lubricant is injected into cylinder bores, the lubricant injection timing may be optimized so that the lubricant comsumption may be reduced considerably. In addition, the air pollution problem due to the adhesion of carbon to the cylinder walls and the combustion of lubricant may be substantially eliminated.

(V) The construction is extremely simple and damage to, and wear of, cams, rollers, fuel pumps and so on may be eliminated. In addition, damage to exhaust valves may be minimized and the noise may be considerably suppressed.

(VI) Since the intake, exhaust and fuel injection valve may be freely controlled, the exhaust gas temperature may be considerably lowered. In addition, the fuel injection delay may be prevented so that the engine performance may be remarkably improved and the NOx emission problem may be eased.

WHAT WE CLAIM IS: 1. An internal combustion engine having means arranged to give an electrical signal representative of the angle or speed of the crankshaft, and computing means which controls in response to that signal a piezo-electric transducer which operates an actuator arranged to operate an engine valve, a fuel injector, or ignition means.

2. An engine as claimed in Claim 1 in which the actuator is a hydraulic actuator controlled by an ON/OFF control valve operated by the output from the computing means.

3. An engine as claimed in Claim 1 or Claim 2 in which the computing means includes reference means for setting in reference crankshaft angles or speeds, and means arranged to give an output when signals computed from the representative signal and the reference signal exceed predetermined limits.

4. An engine as claimed in any of the preceding claims in which the actuator is arranged to operate an inlet valve.

5. An engine as claimed in any of the preceding claims in which the actuator is arranged to operate an exhaust valve.

6. An engine as claimed in any of claims 2-5 in which the hydraulic control valve comprises two sections, each of which has a valve rod having respective small diameter and large diameter sections, a valve sleeve slidable over the valve rod, and a port.

controllable by movement of the valve sleeve in relation to the rod.

7. An engine as claimed in Claim 6 in which in each valve section movement of the sleeve in relation to the rod is in response to oil pressure in the small diameter section.

8. An engine as claimed in any of Claims 2-5 in which the hydraulic control valve has two valve sections, each of which comprises a large diameter piston, a cylinder for the large piston, a small diameter piston driven by oil from the cylinder and a tapered valve body in contact with the small diameter piston and having a surface cooperating with a valve seat when the valve body is moved.

9. An internal combustion engine arranged for operation substantially as herein specifically described with reference to

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **.

limiter 54 and the arithmetic unit 52 and the limiter 55 may be connected in any suitable manner.

11) In stead of the sensor 42 and the converter 41, any suitable tachometer such as a tachogenerator may be used for the detection of the rotational speed of the engine.

12) The limiter 55 in the arithmetic control unit shown in Figure 5 serves to control a maximum injection quantity so that it may consist of a potentiometer or daisy switch by which a driver or operator may easily change a setting value. Alternatively, it may be an automatic device of the type capable of changing a setting value based on a predetermined function such as K1 n2 + K2, where K1 and K2 are constants and n, is the rotational speed of the engine.

13) The valve opening and closing angles or timings may be determined manually.

The novel features and advantages of the present invention may be summarized as follows: (I) Complex cam shaft driving mechanism and valve mechanism-eliminated so that an internal combustion engine may be compact in size with low mechanical losses and high engine efficiency.

(II) Opposed to the conventional internal combustion engines, no skilled and experienced mechanic is required for the engine adjustments such as the engine output, the combustion pressure, the cylinder output balance, the exhaust gas temperature and so on. As a result, the engine may be operated with an optimum efficiency and a number of re-adjustments may be considerably reduced.

(III) The engine may be easily reversed in rotation.

(IV) The valve-timing may be automatically and optimumly changed depending upon the load or rotational speed. In an internal combustion engine of the type wherein lubricant is injected into cylinder bores, the lubricant injection timing may be optimized so that the lubricant comsumption may be reduced considerably. In addition, the air pollution problem due to the adhesion of carbon to the cylinder walls and the combustion of lubricant may be substantially eliminated.

(V) The construction is extremely simple and damage to, and wear of, cams, rollers, fuel pumps and so on may be eliminated. In addition, damage to exhaust valves may be minimized and the noise may be considerably suppressed.

(VI) Since the intake, exhaust and fuel injection valve may be freely controlled, the exhaust gas temperature may be considerably lowered. In addition, the fuel injection delay may be prevented so that the engine performance may be remarkably improved and the NOx emission problem may be eased.

WHAT WE CLAIM IS: 1. An internal combustion engine having means arranged to give an electrical signal representative of the angle or speed of the crankshaft, and computing means which controls in response to that signal a piezo-electric transducer which operates an actuator arranged to operate an engine valve, a fuel injector, or ignition means.
2. An engine as claimed in Claim 1 in which the actuator is a hydraulic actuator controlled by an ON/OFF control valve operated by the output from the computing means.
3. An engine as claimed in Claim 1 or Claim 2 in which the computing means includes reference means for setting in reference crankshaft angles or speeds, and means arranged to give an output when signals computed from the representative signal and the reference signal exceed predetermined limits.
4. An engine as claimed in any of the preceding claims in which the actuator is arranged to operate an inlet valve.
5. An engine as claimed in any of the preceding claims in which the actuator is arranged to operate an exhaust valve.
6. An engine as claimed in any of claims 2-5 in which the hydraulic control valve comprises two sections, each of which has a valve rod having respective small diameter and large diameter sections, a valve sleeve slidable over the valve rod, and a port.

controllable by movement of the valve sleeve in relation to the rod.
7. An engine as claimed in Claim 6 in which in each valve section movement of the sleeve in relation to the rod is in response to oil pressure in the small diameter section.
8. An engine as claimed in any of Claims 2-5 in which the hydraulic control valve has two valve sections, each of which comprises a large diameter piston, a cylinder for the large piston, a small diameter piston driven by oil from the cylinder and a tapered valve body in contact with the small diameter piston and having a surface cooperating with a valve seat when the valve body is moved.
9. An internal combustion engine arranged for operation substantially as herein specifically described with reference to

any of Figures 1, 3, 4, and 5 of the accompanying drawings.
10. An internal combustion engine as claimed in any of the preceding claims including a hydraulic control arrangement constructed and arranged substantially as herein specifically described with reference to Figure 2 or Figure 6 of the accompanying drawings.