JPH0227125Y2 - - Google Patents

Description

[Detailed explanation of the idea]

[Industrial Application Field] The present invention relates to engine structure. [Prior art] In an engine structure in which output is controlled by providing a throttle valve in the intake passage that supplies air-fuel mixture to the combustion chamber and restricting the intake passage, the throttle valve is throttled during low-speed, low-load operation to control the mixture. Limiting the output by controlling the air volume increases pump losses,
Fuel efficiency worsens. For this reason, in order to stop combustion in some cylinders of a multi-cylinder engine during low-speed, low-load operation, the engine structure is equipped with a valve drive device that can stop the opening/closing operation of the intake and exhaust valves. A structure having a hydraulic actuation mechanism for holding the intake and exhaust valves in the closed position has been proposed and adopted. [Problem to be solved by the invention] In such an engine structure, combustion is stopped by holding the intake and exhaust valves of some cylinders in the closed position,
Since the combustion operation is performed only by other cylinders, pump loss is reduced and fuel efficiency is improved. However, if the hydraulic oil supplied to the hydraulic operating mechanism becomes hot and its viscosity decreases, causing a drop in oil pressure, the hydraulic operating mechanism operation becomes uncertain, and the intake and exhaust valves of combustion-stopped cylinders malfunction.
This may lead to problems such as combustion gas being trapped in the combustion chamber, combustion gas flowing back into the intake air, and damage to the intake valve and valve drive device. [Means for Solving the Problems] As mentioned above, the present invention is aimed at solving the above-mentioned problems caused by a decrease in the viscosity of hydraulic oil. A valve drive device that is provided in the system and has a hydraulic actuation mechanism that opens and closes at least a part of the intake valve when hydraulic pressure is supplied and holds it in a closed position when hydraulic pressure is cut off, and controls cutting off of the supply of hydraulic pressure to the hydraulic pressure working mechanism. A hydraulic control valve, a viscosity detection means for detecting the viscosity of hydraulic oil supplied to the hydraulic operating mechanism via the hydraulic control valve, and a low viscosity detection signal from at least the viscosity detection means to control the hydraulic control valve. The gist of the present invention is an engine structure characterized in that it includes a hydraulic control device that stops the supply of hydraulic pressure to the hydraulic operating mechanism. [Function] According to the present invention, when a decrease in the viscosity of the hydraulic oil is detected by the viscosity detection means, the operation of the hydraulic operating mechanism is reliably stopped. [Example] Hereinafter, an example of the present invention will be described in Figures 1 to 1.
This will be explained along with Figure 1. 2 indicates a 4-cylinder engine, the first cylinder is 4, the second
It has a cylinder 6, a third cylinder 8, and a fourth cylinder 10. 12 is a fuel injection device 14 and a throttle valve 16
A first branch passage 18, a second branch passage 20, a third branch passage 22, and a fourth branch passage 2 that communicate with the first cylinder 4 to the fourth cylinder 10, respectively.
It has 4. 26 is the exhaust system, the first cylinder 4
- It has a first branch passage 28, a second branch passage 30, a third branch passage 32, a fourth branch passage 34 and a gathering part 36 which communicate with the fourth cylinder 10, and a catalyst device (not shown) is installed in the gathering part 36. is installed. The first cylinder 4 to the fourth cylinder 10 each have a first primary port P ₁ , a second primary port P ₂ , and a third primary port formed by small-diameter passages.
P ₃ , a fourth primary port P ₄ , and a first secondary port S ₁ , a second secondary port S ₂ , a third secondary port S ₃ , and a fourth secondary port S ₄ formed by large-diameter passages. Intake device 12
The first branch passage 18 to the fourth branch passage 24 are connected to each other. In addition, a first exhaust port E ₁ , a second exhaust port E ₂ , a third exhaust port E ₃ , a fourth exhaust port
_E4 is formed and the first branch passage 2 of the exhaust device 26
It communicates with each of the 8th to 4th branch passages 34. The first cylinder 4 and the fourth cylinder 10 are cylinders that are activated or stopped for combustion depending on the operating conditions, and the second cylinder 6 and the third cylinder 8 are cylinders that are constantly activated for combustion regardless of the operating conditions. Further, each cylinder is supplied with air-fuel mixture only through the first primary port P ₁ to the fourth primary port P ₄ depending on the operating conditions, or is further supplied with the mixture through the first secondary port S ₁ to the fourth secondary port S ₄ . The air-fuel mixture is also supplied. A primary intake valve, a secondary intake valve, and an exhaust valve are appropriately arranged in each of the above ports, and the primary intake valve has a first primary rocker arm RP ₁ and a second primary rocker arm that form this valve driving device.
RP ₂ , a third primary locking arm RP ₃ , and a fourth primary locking arm RP ₄ , and the secondary intake valve is connected to a first secondary locking arm RS ₁ , a second secondary locking arm RS 2 , and a third secondary locking arm RS ₂ forming this valve drive. The exhaust valve is further controlled by the secondary locking arm RS ₃ and the fourth secondary locking arm RS ₄ , which form the valve drive device, including a first exhaust locking arm RE ₁ , a second exhaust locking arm RE ₂ , a third exhaust locking arm RE 3 , and a fourth exhaust locking arm RE ₃ . Lotsuka Arm RE ₄
are operated to open and close, or are held in the closed position, respectively. The configurations of the first cylinder 4 and the fourth cylinder 10 will be explained below with reference to FIGS. 3 and 4, with the first cylinder 4 as a representative. 42 is a cylinder head, 44 is a cylinder block, and 46 is a combustion chamber. PV ₁ is combustion chamber 46
The first primary intake valve SV ₁ is the first primary intake valve disposed at the first primary port P ₁ that communicates with the combustion chamber ₄₆ , and the first
The secondary intake valve EV ₁ is a first exhaust valve disposed at the first exhaust port E ₁ . The first primary intake valve PV ₁ and the first secondary intake valve SV ₁ have a first primary rocker arm RP ₁ and a first secondary rocker arm RS ₁ that are slidably pivoted to the intake rocker shaft 48 and are connected to the camshaft 50 . It is opened and closed or held in the closed position by sliding on the formed intake cam 52 for the first primary rocker arm RP ₁ and intake cam 53 for the first secondary rocker arm RS ₁ . The first exhaust valve EV ₁ is opened and closed by the first exhaust rocker arm RE ₁ slidably supported on the exhaust rocker shaft 54 sliding on the exhaust cam 56 formed on the camshaft 50, or held in the closed position. Next, the configurations of the second cylinder 6 and the third cylinder 8 will be explained with reference to FIGS. 5 and 6, using the second cylinder 6 as a representative. PV ₂ is a second primary intake valve disposed at the second primary port P ₂ communicating with the combustion chamber 60, and SV ₂
is the second secondary port S ₂ communicating with the combustion chamber 60
The second secondary intake valve is located in the EV ₂ .
This is a second exhaust valve disposed at the exhaust port _E2 . The second primary intake valve PV ₂ and the second secondary intake valve SV ₂ are configured such that a second primary locking arm RP 2 and a second secondary locking arm RP ₂ are slidably pivoted to the intake locking shaft 48 , and the second secondary locking arm RP ₂ is connected to the camshaft 50 . It is opened and closed or held in the closed position by sliding on the formed intake cam 62 for the second primary rocker arm RP ₂ and the intake cam 63 for the second secondary rocker arm RS ₂ . The second exhaust valve EV ₂ is opened and closed by the second exhaust rocker arm RE ₂ slidably supported on the exhaust rocker shaft 54 sliding on the exhaust cam 64 formed on the camshaft 50, or held in the closed position. Here, the first primary rocker arm _RP1 , the fourth primary rocker arm _RP4 , the first secondary rocker arm _RS1 to the fourth secondary rocker arm
RS ₄ , the first exhaust rocker arm RE ₁ and the fourth exhaust rocker arm RE ₄ have substantially the same configuration, and the first primary rocker arm RP ₁ is representatively shown in FIGS.
This will be explained along with FIG. The first primary rocker arm RP ₁ is pivotally supported by the intake rocker shaft 48, and has a sliding surface 66 formed at one end on which the intake cam 52 slides, and a cylinder 68 is fixed at the other end. A plunger 70 is slidably installed inside. The plunger 70 is pressed in the protruding direction by a spring 72 and comes into contact with the valve stem end 74 of the primary intake valve RV ₁ . 76 is the 1st primary rock arm RP ₁
A cylinder portion 78 formed in the first primary rocker arm RP ₁ with a hydraulic operating mechanism provided in the
A piston 80 is slidably disposed within the cylinder portion 78, a hydraulic chamber 82 is formed by the left end surface of the piston 80 and the cylinder portion 78, and the piston 8
0 toward the hydraulic chamber 82, a spring 84;
It has a stopper 86 connected to the piston 80 and extending in the direction of the cylinder 68. The hydraulic chamber 82 communicates with a hydraulic pressure supply passage 90 formed in the intake rocker shaft 48 via a passage 88 . 92 indicates a locking mechanism of the piston 80;
Lock plate 94 pivoted to primary locker arm RP ₁ , first primary locker arm RP ₁
A lock pin 104 is slidably disposed in the lock plate 94 and has one end 96 in contact with the cam surface 98 of the intake rocker shaft 48 and the other end 100 in contact with the operating surface 102 of the lock plate 94.
The actuating end 108 of the lock plate 94 is formed to be inserted into or removed from the cylinder portion 78 through the cutout groove 110 of the first primary rocker arm _RP1 . When the piston 80 is in the position shown in FIG. 7, the right end surface 112 of the piston 80 is in contact with the operating end 108 of the lock plate 94, and when the piston 80 is in the right end position in the figure, the engagement groove formed in the piston 80 is in contact with the operating end 108 of the lock plate 94. 114 engages working end 108 of lock plate 94. The stopper 86 has an engagement groove 116 formed at one end.
The rod 11 of the piston 80 passes through the gap 120.
8, the other end 122 is bifurcated and extends to both sides of the cylinder 68, and is slidably engaged with the openings 124 formed on both sides of the cylinder 68, so that the cylinder 68 is in the state shown. An aperture 126 is formed that prevents the plunger 70 from sliding at certain times and allows the plunger 70 to slide when the stopper 86 slides rightward in the figure. This stopper 86 is applied to the first primary rocker arm RP ₁ and the fourth primary rocker arm RP ₄ , as well as the first exhaust rocker arm RE ₁ and the fourth exhaust rocker arm RE ₄ , and is applied to the first secondary rocker arm RS 1 to the fourth secondary rocker arm RS ₁ to the fourth secondary rocker arm RE 4 . A stopper 86' shown in FIG. 10 is applied to the rocker arm _RS4 . This stopper 86' has an opening 126' formed at a position opposite to the stopper 86 (near the right end in the figure) for allowing sliding of the plunger 70. Also, the first
Exhaust rock arm RE ₁ and 4th exhaust rock arm
The hydraulic chamber 82 of RE ₄ communicates with a hydraulic pressure supply passage 91 formed within the exhaust rocker arm 54. The second primary rocker arm RP ₂ and the third primary rocker arm RP ₃ as well as the second exhaust rocker arm RE ₂ and the third exhaust rocker arm RE ₃ have a configuration in which the hydraulic actuation mechanism as described above is not provided. The arm RP ₂ and the second exhaust rocker arm RE ₂ will be explained with reference to FIG. 5. The second primary rocker arm _RP2 is pivotally supported by the intake rocker shaft 48, and has an intake cam 62 at one end.
A cam sliding surface 130 is formed which slides into contact with the second primary intake valve PV 2 , and an adjusting screw 132 which contacts the valve stem end of the second primary intake valve PV ₂ is provided at the other end. The second exhaust rocker arm RE ₂ is the exhaust rocker shaft 54
One end is formed with a cam sliding surface on which the exhaust cam 64 comes into sliding contact, and the other end is provided with an adjusting screw 136 that comes into contact with the valve stem end of the second exhaust valve EV ₂ . It is being In FIG. 2, reference numeral 140 indicates a hydraulic control device that controls the supply of hydraulic oil to the hydraulic operating mechanism 76 in each rocker arm, and engine lubricating oil is used as the hydraulic oil. 142 is the engine lubricating oil supply pump 14
A pressure booster pump 146 is disposed in the discharge passage 142 and increases the hydraulic pressure.
8 is an accumulator that stores the discharge pressure of the pressure booster pump 146; 150 is a first tank that communicates with the discharge passage 142;
A first control valve 154 is disposed in the passage 152, and a second control valve 154 is disposed in a second passage 156 communicating with the discharge passage 142.
Reference numeral 58 denotes hydraulic control means for supplying and controlling the voltage of the power source 160 to the first control valve 150 and the second control valve 154. This hydraulic control means 158 includes a water temperature detection device 162, a negative pressure detection device 1
64, signals from an engine rotational speed detection device 166, an oil temperature detection device 168 that detects the viscosity of hydraulic oil, etc. are input. The hydraulic control means 158 controls the first control valve 150 and the second control valve 154 based on each signal, and the operation of each detection device will be explained here. The water temperature detection device 162 detects the warm-up state of the engine when the coolant temperature is 70° C. or higher, and detects that warm-up is not completed when the coolant temperature is lower than 70° C. The engine rotation speed detection device 166 detects a high engine speed state when the engine rotation speed is 2700 rpm or more, and detects a low engine speed state when the engine speed is less than 2700 rpm. Negative pressure detection device 164 is 80mm during two-cylinder combustion operation
A low load state is detected when Hg negative pressure or 300mmHg negative pressure or more during 4-cylinder combustion operation, and a high load state is detected when the negative pressure is less than these negative pressures. The oil temperature detection device 168 detects the temperature of the hydraulic oil so that the viscosity of the hydraulic oil can be adjusted to the hydraulic operating mechanism 7.
It detects whether or not the oil is supplied to 6 and is sufficient for operation. It detects that the viscosity is sufficient when the oil temperature is below 120℃, and when it exceeds 120℃, the viscosity is insufficient and the operation is incomplete. Detects that there is a risk. When this oil temperature detection device 168 detects that the oil temperature exceeds 120°C, the control means 158 preferentially sets the first control valve 1 to a state in which no oil pressure is supplied to each hydraulic actuating mechanism, regardless of other signal inputs.
50, is operative to control the second control valve 154; The pressure booster pump 146 also includes an eccentric cam 170 connected to a camshaft (not shown), a plunger 172 that operates along the eccentric cam 170, a piston 174 that abuts the plunger 172, and the piston 1.
74 toward the plunger 172, a suction check valve 180 provided in the suction hole 178, and a check valve 184 provided in the discharge hole 182.
have. The accumulator 148 has a piston 186 and a spring 190 that biases the piston 186 toward the pressure accumulation chamber 188. The first control valve 150 is a solenoid 1
92, a plunger 194 energized by the solenoid 192, a spring 196 that presses the plunger 194, and a valve body 20 connected to the plunger 194 and slidably disposed within the cylinder 198.
0, an annular groove 206 formed between the first land 202 and the second land 204 of the valve body 200, a suction hole 208 formed in the cylinder 198, and a discharge hole 21
0, and an atmosphere opening hole 212. Further, the suction hole 208 communicates with the first passage 152, and the discharge hole 208 communicates with the first passage 152.
Reference numeral 10 denotes a hydraulic passage 90 of the intake rocker shaft 48, which communicates with an outer passage 242 located on both outsides of the plugs 240, 240 and a hydraulic passage 91 of the exhaust rocker shaft 54, respectively. The second control valve 154 is the solenoid 2
14, a plunger 216 energized by the solenoid 214, a spring 218 that presses the plunger 216, a valve body 22 connected to the plunger 216 and slidably disposed within the cylinder 220.
2. An annular groove 228 formed between the first land 224 and the second land 226 of the valve body 222, an oil suction hole 234 formed in the cylinder 220, and a discharge hole 2.
32 and an atmosphere opening hole 230. The suction hole 234 communicates with the second passage 156, and the discharge hole 232 communicates with the inner passage 244 between the plugs 240, 240, which is the hydraulic passage 90 of the intake rocker shaft 48. The operation of the embodiment with the above configuration will be explained below with reference to Table 1.

[Table] First, after the engine has been warmed up, the water temperature detection device 162 detects a cooling water temperature of 70°C or higher.
Also, a case will be described in which the oil temperature detection device 168 detects a state where the oil temperature is 120° C. or lower. In the operating region C of FIG. 11, the engine rotation speed detection device 166 detects an engine rotation speed of 2700 rpm
When the above is detected, the hydraulic control means 158 turns off the first control valve 150 and turns off the second control valve 154. At this time, the first
In the control valve 150, the valve body 200 connects the atmosphere opening hole 212 and the discharge hole 210 to cut off the hydraulic pressure in the first passage 152, and the hydraulic passage 91 of the exhaust rocker shaft 54 and the outer passage 24 of the intake rocker shaft 48 communicate with each other.
2,242 will be opened to the atmosphere. Further, in the second control valve 154, the valve body 222 communicates the suction hole 234 and the discharge hole 232, and supplies the hydraulic pressure in the second passage 156 to the inner passage 244 of the intake rocker shaft 48. Therefore, the supply of hydraulic pressure to the first exhaust rocker arm RE ₁ and the fourth exhaust rocker arm RE ₄ is stopped, and the stopper 86 enters the retracted state to hold the plunger 70 in the cylinder 68 in the protruding state, and the first exhaust valve
EV ₁ and the fourth exhaust valve EV ₄ are opened and closed, and the second exhaust rocker arm RE ₂ and the third exhaust rocker arm RE _{3 are} opened and closed.
is constantly opening and closing the second exhaust valve EV ₂ and the third exhaust valve EV ₃ . On the other hand, the supply of hydraulic pressure is also stopped to the first primary rocker arm RP ₁ and the fourth primary rocker arm RP _4, and the stopper 86 is in the retracted state, and the cylinder 6
The first plunger 70 is held in a protruding state.
Primary intake valve PV ₁ and 4th primary intake valve
PV ₄ opens and closes, and the second primary rocker arm RP ₂ and third primary rocker arm RP ₃ always open and close the second primary intake valve PV ₂ and the third primary intake valve PV ₃ . Further, hydraulic pressure is supplied to the first secondary locking arm RS ₁ to the fourth secondary locking arm RS ₄ , and the stopper 86 ′ is in a protruding state to hold the plunger 70 in the cylinder 68 in the protruding state, and the first secondary locking arm RS 1 to the fourth secondary locking arm RS 4 is The valves SV ₁ to 4th secondary intake valve SV ₄ are opened and closed. Through the above-described operation, all the intake valves and exhaust valves of the first cylinder 4 to the fourth cylinder 10 are opened and closed, and combustion operation is performed. Next, in the operating region B of FIG. 11, the engine rotation speed detection device 166 detects the engine rotation speed.
If less than 2700 rpm is detected and the negative pressure detection device 164 detects a relatively small negative pressure, the hydraulic control means 158 turns off the first control valve 150 and turns on the second control valve 154. At this time, in the first control valve 150, the valve body 200 connects the atmosphere opening hole 212 and the discharge hole 210 to cut off the hydraulic pressure in the first passage 152, and the hydraulic passage 91 of the exhaust rocker shaft 54 and the intake rocker shaft 48
The outer passages 242, 242 of are opened to the atmosphere. Further, in the second control valve 154, the valve body 222 communicates the atmosphere opening hole 230 and the discharge hole 232, cuts off the hydraulic pressure in the second passage 156, and opens the inner passage 244 of the intake rocker shaft 48 to the atmosphere. For this reason, the first secondary locking arm RS ₁ ~
The supply of hydraulic pressure to the fourth secondary locker arm RS ₄ is stopped, the stopper 86' is in the retracted state, and the plunger 70 in the cylinder 68 is unlocked and becomes slidable, so that the first secondary intake valve
The opening/closing operations of the fourth secondary intake valves SV ₁ to SV ₄ are stopped and held in the closed position. Due to the above-mentioned operation, the first cylinder 4 to the fourth cylinder 10 are operated as the first primary intake valve PV ₁ to the fourth primary intake valve PV ₄ and the first exhaust valve EV ₁ to the fourth exhaust valve, respectively.
EV ₄ is opened and closed and combustion is activated. Next, in the operating region A of FIG. 11, the engine rotation speed detection device 166 detects the engine rotation speed.
If less than 2700 rpm is detected and the negative pressure detection device 164 detects a relatively large negative pressure, the hydraulic control means 158 turns on the first control valve 150 and turns on the second control valve 154. At this time, in the first control valve 150, the valve body 200 communicates the suction hole 202 and the discharge hole 210, and transfers the hydraulic pressure in the first passage 152 to the exhaust rocker shaft 54.
hydraulic passage 91 and the outer passage 2 of the intake rocker shaft 48
42,242. Further, the second control valve 154 has a valve body 222 that is connected to the atmosphere opening hole 2.
30 and the discharge hole 232 to shut off the hydraulic pressure in the second passage 156, and the inner passage 24 of the intake rocker shaft 48
4 is opened to the atmosphere. Therefore, hydraulic pressure is supplied to the first exhaust rocker arm RE ₁ and the fourth exhaust rocker arm RE ₄ , and to the first primary rocker arm RP ₁ and the fourth primary rocker arm RP ₄ , and the stopper 86 becomes in a protruding state, and the pressure inside the cylinder 68 is In order to unlock the plunger 70 and make it slidable, the first exhaust valve EV ₁ , the fourth exhaust valve EV ₄ , and the first primary intake valve PV ₁
The opening/closing operation of the fourth primary intake valve PV ₄ is stopped and held in the closed position. As a result of the above-described operation, the opening/closing operations of all intake and exhaust valves in the first cylinder 4 and the fourth cylinder 10 are stopped, the cylinders are held in the closed position, and combustion is stopped. Further, in the second cylinder 6 and the third cylinder 8, only the second primary intake valve PV ₂ and the third primary intake valve PV ₃ and the second exhaust valve EV ₂ and the third exhaust valve EV ₃ are operated to open and close. Combustion is performed only by the valves that are opened and closed. In the above operation, when the negative pressure signal of the negative pressure detection device 164 changes from region B to region A in FIG. When changing from region A to region B, the intake manifold negative pressure is set to 80 mmHg in the two-cylinder combustion state so that the change in output between the two regions is minimized. The operation after completion of warm-up has been described above, but next, the operation during a cold period when the water temperature detection device 162 detects a cooling water temperature of less than 70° C. will be explained. When the engine is cold, the engine is always in four-cylinder combustion operation in order to quickly complete the warm-up operation to improve the exhaust gas purification characteristics, and to quickly raise the cooling water temperature to increase the amount of heat generated by the cabin heater device (not shown). do. That is, when the engine rotational speed detection device 166 detects an engine rotational speed of less than 2700 rpm, the hydraulic control means 158 turns off the first control valve 150 and turns on the second control valve 154, thereby controlling the first cylinder. 4～
The fourth cylinder 10 has the first primary intake valve PV ₁ to the fourth primary intake valve as shown in the above-mentioned operating region B.
Only PV ₄ and the first to fourth exhaust valves EV ₁ to EV ₄ are opened/closed to perform the combustion operation. Further, the engine rotation speed detection device 166 detects the engine rotation speed.
When 2700 rpm or more is detected, the hydraulic control means 158 turns off the first control valve 150 and turns off the second control valve 154, so that the first cylinder 4 to the fourth cylinder 10 are in the above-mentioned operating range C. As shown in , all intake and exhaust valves are opened and closed to perform combustion operation. Next, in each of the above operations, the oil temperature detection device 16
8 detects an abnormally high temperature state in which the oil temperature exceeds 120° C., the hydraulic control means 158 turns off the first control valve 150 and holds the second control valve 154 on. Therefore, as shown in the above-mentioned operating region B, the first cylinder 4 to the fourth cylinder 10 are opened to the atmosphere by stopping the supply of hydraulic pressure to each rocker arm, and the first primary intake valve PV 1 to the fourth primary intake valve PV ₁ to the fourth primary Only the intake valve PV ₄ and the first to fourth exhaust valves EV ₁ to EV ₄ are opened/closed to perform the combustion operation. As shown in each operation above, the oil temperature detection device 168
detects a high temperature, the viscosity of the hydraulic oil decreases, and the pressure booster pump 146, accumulator 148,
Oil leakage from the first control valve 150, the second control valve 154, each hydraulic actuating mechanism 76, etc. tends to become large and operation becomes uncertain, but according to this embodiment, in high temperature conditions, the first control valve By turning off the valve 150 and turning on the second control valve 154, the hydraulic pressure supply to the hydraulic operating mechanism of each rocker arm is stopped, resulting in the effect that the operation is stable regardless of oil leakage. Further, according to this embodiment, it is possible to prevent combustion gas from being trapped in the combustion chamber due to malfunction of each intake/exhaust valve, backflow of combustion gas into the intake air, damage to the intake valve, damage to the hydraulic operating mechanism 76, etc. It has an extremely effective prevention effect. In the above embodiment, the viscosity of the hydraulic oil is detected by detecting the oil temperature, but an oil pressure detection device may be used based on the property that the oil pressure decreases when the viscosity decreases. Further, the configuration may be such that the water temperature is detected instead of the oil temperature. When using a hydraulic pressure detection device, the discharge passage 14 of the lubricating oil supply pump 144
Hydraulic pressure of 2 is 0.3Kg/ ^cm2 or less, or booster pump 1
It is detected that the viscosity has decreased when the oil pressure of the discharge hole 182 of No. 46 is 1.5 Kg/cm ² or less.

[Brief explanation of the drawing]

Fig. 1 is a schematic explanatory plan view of an embodiment of the present invention, Fig. 2 is a schematic explanatory diagram showing a hydraulic actuation mechanism and hydraulic control means of an embodiment, and Fig. 3 corresponds to the - cross section of Fig. 2. Engine cross-sectional explanatory diagram, No. 4
The figure is an explanatory diagram of an engine cross section corresponding to the - cross section in Fig. 2, Fig. 5 is an explanatory diagram of an engine cross section corresponding to the - cross section in Fig. 2, and Fig. 6 is an explanatory diagram of an engine cross section corresponding to the - cross section in Fig. 2. Fig. 7 is a schematic explanatory diagram showing a rocker arm of one embodiment, Fig. 8 is a - cross-sectional explanatory diagram of Fig. 7, Fig. 9 is an explanatory - cross-sectional diagram of Fig. 7, and Fig. 10 is a schematic explanatory diagram of a - cross-sectional diagram of Fig. 7. Another cross-sectional explanatory view corresponding to FIG. 11 is an operational characteristic diagram of one embodiment. 2...4 cylinder engine, 4, 6, 8, 10...
1st cylinder to 4th cylinder, 12... Intake system, P ₁ ~
P ₄ ... 1st to 4th primary port, S ₁ to S ₄ ...
...1st to 4th secondary port, E ₁ to _{E 4} ... 1st to 4th exhaust port, RP ₁ to _{RP 4} ... 1st to 4th
Primary lock arm, RS ₁ ~ RS ₄ ... 1st ~
4th secondary rocker arm, RE ₁ to _{RE 4} ... 1st to 4th exhaust rocker arm, PV ₁ to _{PV 4} ... 1st
~4th primary intake valve, SV ₁ ~SV ₄ ... 1st ~
Fourth secondary intake valve, EV ₁ to EV ₄ ... First to fourth exhaust valve, 68 ... Cylinder, 70 ... Plunger, 76 ... Hydraulic operation mechanism, 78 ... Cylinder,
80...piston, 86...stopper, 140...
...Hydraulic control device, 158...Hydraulic control means, 15
0...First control valve, 154...Second
control valve.

Claims (1)

[Scope of utility model registration request] A valve drive device that is installed in a valve system that opens and closes the intake valve or exhaust valve of an engine, and has a hydraulic operating mechanism that drives at least a portion of the intake valve to open and close when hydraulic pressure is supplied, and holds it in the closed position when hydraulic pressure is cut off. , a hydraulic control valve for controlling supply cutoff of hydraulic pressure to the hydraulic operating mechanism, a viscosity detecting means for detecting the viscosity of the hydraulic oil supplied to the hydraulic operating mechanism via the hydraulic control valve, and at least the viscosity detecting means. An engine structure comprising: a hydraulic control device that controls the hydraulic control valve based on a low viscosity detection signal from the hydraulic control valve to stop supplying hydraulic pressure to the hydraulic operating mechanism.