JP4082919B2 - Intake valve opening timing detection device for the engine under test - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an intake valve opening timing detection apparatus in a test target engine.
[0002]
[Prior art]
Recently, when detecting the opening timing of the intake valve in the engine, by supplying fuel to the test target engine and actually burning it, by rotating the crankshaft by external drive means, A cold test may be performed to detect the opening timing of the intake valve. In such a cold test, the closing timing of the intake valve and the opening / closing timing of the exhaust valve may be detected together.
[0003]
By the way, in the cold test as described above, for example, an engine test is performed by rotating the crankshaft by an external drive means even for an engine in the middle of assembly where a fuel injection nozzle, a spark plug or the like is not yet mounted. Therefore, even if it is necessary to carry out a rework work by the engine test, it is possible to reduce the cost by reducing the number of rework steps.
[0004]
As a configuration for detecting the opening timing of the intake valve in the test target engine by such a cold test, conventionally, as shown in, for example, Japanese Patent Publication No. 2-55738, the cylinder internal space in the test target engine is reduced. In order to detect the pressure change in the intake port, in a state where air is released and air is supplied from an air supply source provided outside the engine to the cylinder through a regulator toward the intake port provided in the cylinder. When the crankshaft is rotated by the external drive means, the intake valve opening timing is determined based on the detection information of the pressure detection means based on the detection information of the pressure detection means. There was something configured to detect as.
[0005]
[Problems to be solved by the invention]
By the way, the engine is generally provided with a plurality of cylinders, and the intake port and the intake valve are provided separately for each of the plurality of cylinders, and a plurality of intake air provided for each of the plurality of cylinders. An intake manifold for distributing and supplying combustion air from the air cleaner to the port is assembled.
[0006]
However, in the above-described conventional configuration, air is supplied to the intake port provided for each cylinder, and the opening timing of the intake valve is detected by detecting the pressure change in the intake port. Since the valve timing detection process cannot be performed in the state where the intake manifold as described above is assembled, the valve timing detection process as described above is performed by assembling the cylinder head provided with the intake valve and the exhaust valve. After that, it is necessary to assemble the intake manifold in a separate process, and in the process of assembling the cylinder head, it is impossible to assemble the intake manifold together, which has been a factor in reducing productivity in the engine assembly process. .
[0007]
Further, in the above-described conventional configuration, if the engine has a plurality of cylinders, it is necessary to individually connect an air supply pipe to each of the plurality of intake ports or to provide a pressure detection means. It took a long time and there was a risk of reducing productivity in the engine assembly process.
[0008]
The present invention has been made paying attention to such a point, and an object of the present invention is to provide an intake valve opening timing detection device in a test target engine that can improve productivity in an engine assembly process. is there.
[0009]
[Means for Solving the Problems]
The intake valve opening timing detection device for a test engine according to claim 1 is assembled to each of a plurality of cylinders such that an intake valve and an exhaust valve are opened and closed as the crankshaft rotates, and an intake manifold Connected to the crankshaft in the engine to be tested, forcibly rotating the crankshaft, rotational phase detecting means for detecting the rotational phase of the crankshaft, and the interior of the intake manifold Pressure detection means for detecting pressure, detection information of the pressure detection means in a state in which the crankshaft is rotated by the external drive means with the intake portion of the intake manifold closed, and the rotation Based on the detection information of the phase detection means, the internal pressure of the intake manifold tends to increase from a decreasing trend The rotational phase change, characterized in that it is constituted by a timing detection means for detecting as an open timing of the intake valve.
[0010]
That is, not only the intake valve and exhaust valve but also the crankshaft of the engine under test assembled with the intake manifold connected to the intake port is rotated by the external drive means, With the part closed, the internal pressure of the intake manifold is detected by the pressure detecting means, and the rotational phase of the crankshaft is detected by the rotational phase detecting means. Then, the rotational phase at which the internal pressure of the intake manifold detected by the pressure detecting means changes from a decreasing tendency to an increasing tendency is detected as the intake valve opening timing.
[0011]
In other words, when the crankshaft is rotated by the external driving means, the intake stroke in which the piston under test in the cylinder under test with the intake valve opened and the air is sucked into the cylinder from the intake port, A compression stroke in which the piston rises in the cylinder and compresses the air in the cylinder with the intake valve and exhaust valve closed, and the piston descends and the air in the cylinder expands with the intake valve and exhaust valve closed The expansion stroke and the exhaust stroke in which the piston rises in the cylinder and the air in the cylinder is discharged from the exhaust port while the exhaust valve is open are executed.
The operation timing at which the intake valve opens is when the piston rises and approaches the top dead center in the exhaust stroke. When the intake valve is opened, the air pushed out by the piston raising operation becomes the intake manifold. The pressure inside the intake manifold temporarily increases to a high pressure by being pushed out to the side, but thereafter, the internal pressure of the intake manifold decreases due to the intake operation by executing the intake stroke. It will be. The pressure decrease due to the execution of the intake stroke and the pressure increase due to the intake valve opening operation are repeated, but the internal pressure of the intake manifold detected by the pressure detection means tends to increase due to the decreasing trend. The rotational phase that changes to corresponds to the operation timing at which the intake valve opens.
[0012]
Even when the intake manifold is assembled as described above, the opening timing of the intake valve can be detected, and the intake manifold can be assembled together in the work process of assembling the intake valve and the exhaust valve.
In addition, since the opening timing of the intake valve is detected based on the internal pressure of the intake manifold, even in an engine including a plurality of cylinders, each of the plurality of intake ports is provided for each of the plurality of intake ports as in the conventional configuration. There is no need for troublesome work such as providing a separate pressure detecting means, and work efficiency can be improved.
[0013]
Therefore, it has become possible to provide an intake valve opening timing detection device in a test target engine that can improve productivity in an assembly process of the engine.
[0014]
An intake valve opening timing detection apparatus for an engine to be tested according to claim 2 is the apparatus according to claim 1, wherein the timing detection unit is configured to detect the timing per unit time after the internal pressure of the intake manifold changes from a decreasing tendency to an increasing tendency. When an increase state determination process for determining whether or not the change amount of the internal pressure has reached a set value, and when the change amount per unit time of the internal pressure is determined to be the set value in the increase state determination process, the change And a phase calculation process for obtaining a rotation phase on the upper side in the rotation direction by the set amount from the rotation phase when the amount reaches the set value as a rotation phase that changes from the decreasing tendency to the rising tendency. It is characterized by being.
[0015]
As described above, when the intake valve is opened, the internal pressure of the intake manifold rises. Therefore, when the internal pressure changes from a decreasing tendency to an increasing tendency, the intake valve opening timing is the same. It is difficult to accurately detect when the pressure starts to increase with the opening of the pressure based on the detection result of the pressure detection value.
If explanation is added based on the experimental data by the present applicant, as shown in FIG. 9, the internal pressure of the intake manifold rises. Therefore, the intake manifold starts from the time (X2) when the internal pressure changes from a decreasing tendency to an increasing tendency. There is a slight time delay until the change amount per unit time of the internal pressure reaches the set value (X1), and the pressure detection value immediately after the intake valve is opened is a gradual change. It is difficult to accurately detect when the pressure starts to increase with opening.
[0016]
Therefore, the rotation phase at the time when the amount of change per unit time after the internal pressure changes from a decreasing trend to an increasing trend becomes the set value is obtained, and the rotation phase on the upper side in the rotation direction is calculated from the rotation phase by the set amount. Is obtained as a rotational phase that changes from a decreasing tendency to an increasing tendency.
[0017]
Thus, the rotational phase at which the internal pressure of the intake manifold changes from a decreasing tendency to an increasing tendency can be detected as accurately as possible corresponding to the opening timing of the intake valve. A suitable means is obtained.
[0018]
According to a third aspect of the present invention, there is provided the opening timing detection device for an intake valve in an engine to be tested according to the first or second aspect, wherein the timing detection means samples a pressure detection value detected by the pressure detection means at every set period. In addition, a moving average value for each set number of the sampled sampling values is obtained, and a rotational phase at which the moving average value changes from a decreasing tendency to an increasing tendency is detected as an opening timing of the intake valve. It is characterized by being.
[0019]
That is, since the moving average value is obtained for each set number of sampling values for the pressure detection values sampled at each set cycle, for example, the pressure detection value detected by the pressure detection means is caused by disturbance. Even if a value that changes greatly temporarily is detected, the detected value is averaged and averaged by obtaining the moving average value. Therefore, it is possible to suppress the occurrence of errors due to this, and to obtain a suitable means for implementing the first or second aspect.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an engine test apparatus including an intake valve opening timing detection apparatus in a test target engine according to the present invention will be described with reference to the drawings.
As shown in FIG. 1, this engine test apparatus is connected to a crankshaft 4 of a test target engine 1 attached to a pallet P, and has an external drive means including an electric motor 2 for forcibly rotating the crankshaft 4. 3. The encoder 5 as a rotation phase detecting means for detecting the rotation phase of the crankshaft 4 by detecting the rotation of the crankshaft 4; the rotation speed of the electric motor 2 is controlled; The control unit H is configured to determine whether or not the timing of opening / closing operation of the intake valve and the exhaust valve is appropriate based on detection information of various sensors S and the encoder 5 as described later.
[0021]
The encoder 5 outputs a reference signal of one pulse every time the crankshaft 4 makes one rotation to be a reference for the rotation phase, and outputs a pulse one by one every time the crankshaft 4 rotates by a predetermined unit angle. Is configured to output. This timing pulse is output at 3600 pulses per revolution.
[0022]
In this engine test apparatus, the engine 1 to be tested is transported to a predetermined test setting position by a transport device such as a conveyor while being mounted on the pallet P, and rotation of the electric motor 2 in the external drive means 3 is performed by an operator. The shaft 2a is connected to the crankshaft 4 via a connecting tool CP. When the test target engine 1 is thus transported to the test setting position, a test given in advance with a barcode is performed. The identification information ID for management of the target engine is read by the barcode sensor 30, and the identification information ID is input to the control unit.
The external drive means 3 is configured to be switchable between a state in which the crankshaft 4 is rotated in a normal rotation direction and a state in which the crankshaft 4 is rotated in a reverse rotation direction, and can rotate the crankshaft 4 at different rotational speeds. It has become.
[0023]
Then, with the external drive means 3 connected in this manner, the control unit H controls the rotational speed of the electric motor 2 to be the rotational speed for testing based on the operation command, and the electric motor 2 By forcibly rotating the crankshaft 4 by the rotational operation, the piston 7 is moved up and down and the intake valve 9 and the exhaust valve 10 are opened and closed as shown in FIG. Then, an expansion stroke and an exhaust stroke are sequentially repeated, and a cold test is performed in which various engine tests such as opening and closing timings of the intake valve 9 and the exhaust valve 10 are performed without actually burning.
[0024]
Further, in this engine test apparatus, when performing the above-described cold test, the compression top dead center of the test target engine becomes a reference for various measurements. The compression top dead center TDC of the reference cylinder 6a is obtained, and the opening / closing operation timing of the intake valve 9 and the exhaust valve 10 mounted on each cylinder 6 is measured using the compression top dead center of the reference cylinder 6a as a reference point. The pass / fail of the test target engine is determined based on whether the opening / closing operation timing is within an appropriate range.
[0025]
As shown in FIG. 2, the test target engine 1 is a four-cylinder four-cycle diesel engine, and includes a crankshaft 4 connected to a piston 7 of each cylinder 6 via a connecting rod 8, an intake valve 9, and A camshaft 11 having a cam for opening and closing the exhaust valve 10 is provided, and the crankshaft 4 and the camshaft 11 are connected by a gear-type interlocking mechanism 12. This gear-type interlocking mechanism 12 rotates a crankshaft gear 12a provided on the crankshaft 4 and a camshaft gear 12c provided on the camshaft 11 in an interlocking manner by meshing the gears via a relay gear 12b. The number of gear teeth is set so that when the crankshaft 4 rotates twice, the camshaft 11 rotates once in the same direction.
As the crankshaft 4 is rotated, the piston 7 of each cylinder 6 is moved up and down, and the camshaft 11 is rotated to open and close the intake valve 9 and the exhaust valve 10. The fuel injection nozzle that injects fuel into the cylinder is not installed at this test stage. And it is the structure which connects the pressure sensor 14 for detecting the pressure in the cylinder which is one of the sensors S using the mounting hole 13 for mounting | wearing with this fuel-injection nozzle.
[0026]
The connection configuration of the pressure sensor 14 will be described. As shown in FIG. 3, the length of the reference cylinder 6a is about 800 to 900 mm with respect to the mounting hole 13 using a connection jig 15. A length of the hydraulic hose 16 is connected, and the pressure sensor 14 is connected to the tip of the hydraulic hose 16. The pressure sensor 14 is connected through the hydraulic hose 16 in this way because the pressure in the cylinder 6a is high, so that the connection location is not accidentally disconnected or damaged during inspection work. The hydraulic hose 16 which is excellent and flexible and easy to work is used to exhibit a buffer function so as to reduce the high pressure in the cylinder. The pressure sensor 14 is configured to detect the pressure in the reference cylinder 6a connected through the hydraulic hose 16 as it is, and is configured to be used for processing for detecting the compression top dead center of the reference cylinder 6a.
For the other three cylinders 6 other than the reference cylinder 6a, the mounting hole 13 is closed by a closing member.
[0027]
Further, a hydraulic pressure having a length of about 800 to 900 mm using a connecting jig 19 with respect to an intake port 18 of an intake manifold 17 for supplying air into each cylinder 6 through each intake valve 9. A hose 20 is connected, and a pressure sensor 21, which is one of sensors for detecting the internal pressure of the intake manifold 17, is connected to the tip of the hydraulic hose 20. The pressure sensor 21 is used for processing for inspecting the opening / closing timing of the intake valve 9.
[0028]
Next, a processing procedure by the engine test apparatus will be described.
As shown in FIG. 4, the test target engine 1 is transported to the test setting position, and the external drive means 3 is connected to the crankshaft 4 (step 1). At this time, the identification information ID for management of the test target engine 1 is read, and the identification information ID is input to the control unit H (step 2). When the connection work of the external drive means 3 is completed and the worker commands the start of detection, the control unit H executes a detection process of the compression top dead center TDC (hereinafter abbreviated as a TDC detection process) (step). 3). When the TDC detection process ends, the valve timing is detected with reference to the compression top dead center TDC. That is, a process for detecting the opening timing of the intake valve 9, a process for detecting the closing timing of the intake valve 9, and a process for detecting the opening timing of the exhaust valve 10 are executed. The process which determines the pass / fail of the test object engine 1 by whether it is an appropriate state is performed (steps 4-7).
[0029]
When the control unit H executes the TDC detection process, the control unit H sets the pressure detection value detected by the pressure sensor 14 in a state where the crankshaft 4 is rotated in the normal rotation direction by the external driving unit 3. Based on this, the rotational phase of the crankshaft 4 when the pressure in the cylinder reaches the maximum value in one cycle of the reference cylinder 6a is obtained as the first preliminary compression top dead center, and the external drive means 3 In the state in which 4 is rotated in the reverse rotation direction, the rotation phase of the crankshaft 4 when the pressure in the cylinder reaches the maximum value in one cycle is determined based on the pressure detection value detected by the pressure sensor 14. Obtained as the second preliminary compression top dead center, and further, the rotational phase of the crankshaft 4 positioned at the center between the first preliminary compression top dead center and the second preliminary compression top dead center is determined as the compression top dead center of the engine. As you ask It has been made. Here, the one cycle corresponds to a cycle in which the test target engine 1 performs each of the intake stroke, the compression stroke, the expansion stroke, and the exhaust stroke as the crankshaft 4 rotates. That is, the crankshaft 4 rotates twice during this one cycle.
[0030]
In addition, when the first preliminary compression top dead center is obtained and when the second preliminary compression top dead center is obtained, the pressure detection value detected by the pressure sensor 14 is sampled every set period. At the same time, a moving average value is obtained for each set number of sampled sampling values, and the rotational phase of the crankshaft 4 when the moving average value reaches the maximum value in one cycle is determined in the cylinder. The rotation phase of the crankshaft 4 when the pressure reaches the maximum value is obtained.
[0031]
Next, the TDC detection processing by the control unit H will be described based on the flowchart shown in FIG.
Rotational speed at which the crankshaft 4 is rotated in the normal rotation direction (hereinafter referred to as the forward rotation direction) by the external drive means 3 and the rotation speed of the crankshaft 4 is 60 rotations per minute based on the detection information of the encoder 5 The speed is controlled so as to be (60 rpm) (step 31). In a state of rotating in the forward direction at such a set speed, the pressure detection value in the pressure sensor 14 connected to the cylinder of the reference cylinder 6a is sampled every set unit time, and the sampled value is a predetermined number. The process of obtaining the moving average value (51 pieces) is sequentially executed (steps 32 and 33). This moving average value is obtained every time the encoder 5 outputs a timing pulse.
[0032]
Further, the control unit H continuously executes the process of integrating the timing pulses output from the encoder 5, and when the reference signal output every rotation is input, the integrated value of the timing pulses at that time Is reset to zero, and such processing is repeatedly executed. Then, a process of obtaining the rotational phase of the crankshaft 4 when the moving average value becomes maximum in one cycle as the first preliminary compression top dead center TDC (Y1) is executed (step 34). Thus, steps 31 to 34 are repeatedly executed until the first preliminary compression top dead center TDC (Y1) is obtained.
[0033]
When the first pre-compression top dead center TDC (Y1) is obtained, the crankshaft 4 is then rotated in the reverse direction by the external driving means 3 so that the rotational speed (60 rpm) is 60 revolutions per minute. In the rotation state in the reverse rotation direction, the pressure detection value is sampled and the sampled value is moved by a predetermined number (51) in the same manner as the processing in the normal rotation state. The processing for obtaining the value is sequentially executed (steps 35, 36, 37, 38), and the rotational phase of the crankshaft 4 when the moving average value becomes maximum in one cycle is determined as the second preliminary compression top dead center TDC ( Y2) is obtained (step 39). Then, Steps 36 to 39 are repeatedly executed until the second preliminary compression top dead center TDC (Y2) is obtained.
When the second preliminary compression top dead center TDC (Y2) is obtained, the rotation operation of the electric motor 2 is stopped, and the second preliminary compression top dead center is positioned at the center between the first preliminary compression top dead center and the second preliminary compression top dead center. The rotational phase of the crankshaft 4 is determined as the compression top dead center of the engine (steps 40, 41, 42).
[0034]
When the explanation is added, FIG. 7 shows the output value of the encoder 5 and the pressure detection value (moving average value) in a state in which the rotation phases correspond to each other. Of these, FIG. 7 (a) shows a change in the rotation state in the forward rotation direction, and FIG. 7 (b) shows a change in the rotation state in the reverse rotation direction.
In a 4-cycle engine, the piston 7 reciprocates twice during the intake stroke, compression stroke, expansion stroke, and exhaust stroke, so there are two top dead centers of the compression stroke and the exhaust stroke. In the exhaust stroke, the pressure in the cylinder does not become high because the exhaust valve 10 is open, and the pressure in the cylinder is maximized only at the top dead center (compression top dead center) in the compression stroke. Therefore, as shown in the figure, there is a point (compression top dead center) at which the pressure in the cylinder becomes maximum during one rotation of the crankshaft 4.
Therefore, angle information (A) between the point at which the pressure in the forward rotation state becomes maximum in one cycle (first preliminary compression top dead center) and the reference signal on the upper side in the rotational direction than that, The angle information (B) between the point at which the pressure in the reverse rotation state becomes the maximum in one cycle (second preliminary compression top dead center) and the reference signal on the lower side in the rotational direction is represented by the encoder 5. As shown in FIG. 6 (c), it corresponds to an angle that is an average value of the angle information (A) and the angle information (B) with reference to the normal rotation state. The phase, that is, the rotational phase of the crankshaft 4 positioned at the center between the first preliminary compression top dead center and the second preliminary compression top dead center is obtained as the true compression top dead center TDC. The compression top dead center TDC obtained in this way is stored in correspondence with the rotation phase obtained from the detection signal of the encoder 5. Thereafter, the operation timing of the intake valve 9 and the exhaust valve 10 is detected based on the compression top dead center thus obtained.
Therefore, the calculation means 100 for obtaining the compression top dead center of the test target engine using the control unit H is configured.
[0035]
Further, when the control unit H executes the process of detecting the opening timing of the intake valve 9, the detection information of the pressure sensor 21 in the state where the crankshaft 4 is rotated by the external drive means 3, and Based on the detection information of the encoder 5, the rotation phase at which the internal pressure of the intake manifold 17 detected by the pressure sensor 21 changes from a decreasing tendency to an increasing tendency is detected as the opening timing of the intake valve 9. . In other words, ascending state determination for determining whether or not the amount of change per unit time after the internal pressure of the intake manifold 17 detected by the pressure sensor 21 has changed from a decreasing tendency to an increasing tendency has become a set value. When it is determined that the amount of change in internal pressure per unit time has reached the set value in the processing and its rising state determination processing, the direction of rotation is the amount of the set amount from the rotation phase when the amount of change has reached the set value. Phase calculation processing for obtaining the rotation phase on the upper side as a rotation phase that changes from a decreasing tendency to an increasing tendency is performed.
[0036]
Next, intake valve opening timing detection processing by the control unit H will be described based on the flowchart shown in FIG.
The external drive means 3 rotates the crankshaft 4 in the forward rotation direction, and based on the detection information of the encoder 5, the speed control is performed so that the rotational speed of the crankshaft 4 becomes a rotational speed (60 rpm) of 60 revolutions per minute. (Step 51). In a state of rotating in the forward rotation direction at such a set speed, the pressure detection value in the pressure sensor 21 connected to the intake manifold 17 is sampled every set unit time, and the sampled value is a predetermined number (51 The processing for obtaining the moving average value is performed sequentially (steps 52 and 53). This moving average value is obtained every time the encoder 5 outputs a timing pulse.
[0037]
And the process which calculates | requires the raise variation | change_quantity per unit time of the calculated | required moving average value is performed (step 54), and after the moving average value changes from a decreasing tendency to an increasing tendency, the increasing change amount per unit time is set value. It is determined whether or not the above has been reached (step 55). This process corresponds to the rising state determination process. Steps 51 to 54 are repeatedly executed until it is determined that the amount of increase in change per unit time is equal to or greater than the set value. Then, when it is determined that the increase amount of change per unit time is equal to or greater than the set value, the rotation phase on the upper side in the rotation direction by the set amount from the rotation phase when the increase amount of change becomes the set value, A phase calculation process for obtaining a rotation phase that changes from a decreasing tendency to an increasing tendency is executed (step 56).
In this way, the rotational phase at which the pressure detection value in the pressure sensor 21 changes from a decreasing tendency to an increasing tendency is detected as the opening timing of the intake valve 9 on the basis of the compression top dead center detected in the TDC detection process. To do.
Accordingly, the timing detection means 101 that detects the opening timing of the intake valve using the control unit H is configured.
[0038]
In other words, FIG. 8 shows a change in the pressure detection value of the pressure sensor 21 when the crankshaft 4 is rotated in the forward rotation direction by the external driving means 3 with reference to the rotational phase information of the crankshaft 4. Is associated with the change in the pressure inside each cylinder and the operation timing of the intake valve 9 and the exhaust valve 10. Incidentally, in FIG. 8, # 1 indicates the reference cylinder 6a, # 2 indicates the second cylinder 6, # 3 indicates the third cylinder 6, and # 4 indicates the fourth cylinder 6, “EX” indicates a state where the exhaust valve 10 in each cylinder 6 is open, and “IN” indicates a state where the intake valve 9 in each cylinder 6 is open. As is apparent from this figure, when the intake valve 9 is opened in any of the cylinders 6, the pressure inside the intake manifold 17 begins to rise. That is, in the cylinder, when the piston rises and is almost close to top dead center, when the intake valve 9 is opened, the air pushed out by the piston raising operation is pushed out to the intake manifold 17 side. This is because the pressure inside the intake manifold 17 temporarily increases, and thereafter gradually decreases due to the intake operation.
[0039]
FIG. 9 shows an enlarged view in a predetermined region Q including the timing at which the intake valve 9 in FIG. 8 opens. As is apparent from this figure, the timing at which the intake valve 9 is opened is assumed. At that time, the pressure detection value will change from a decreasing trend to an increasing trend, but the change is slow and it is difficult to detect the opening timing from the pressure detection value information. The rotational phase X2 on the upper side in the rotational direction by the set amount C from the rotational phase X1 when the amount of change to the upward side becomes the set value is obtained as the rotational phase that changes from the decreasing tendency to the upward tendency. It is.
[0040]
[Another embodiment]
Hereinafter, other embodiments are listed.
[0041]
(1) In the above embodiment, the timing detection means determines whether or not the amount of change per unit time after the internal pressure of the intake manifold has changed from a decreasing tendency to an increasing tendency has become a set value. When it is determined that the amount of change per unit time of the internal pressure has reached the set value in the processing and the rising state determination processing, the amount of rotation is rotated by the set amount from the rotation phase when the amount of change has reached the set value. Although the phase calculation processing for obtaining the rotational phase on the upper side in the direction as the rotational phase that changes from the decreasing tendency to the increasing tendency is executed, respectively, instead of such a configuration, the following configuration is also possible. Good.
That is, for the set phase time in which the pressure detection value (moving average value) is detected within a predetermined phase range including the opening timing of the intake valve, the setting for determining the rise is compared with the previous data. It is determined whether or not it has increased by an amount or more, and if it has increased by an amount greater than or equal to the increase determination set amount, it may be determined as a rotation phase that starts to change from the decreasing tendency to the increasing tendency at that time. .
[0042]
(2) In the above embodiment, the pressure detection value is sampled at each set cycle, and the moving average value for each set number of the sampled sampling values is obtained. However, instead of such processing, detection is performed. Various configurations such as processing that removes special data that changes locally such that the rate of change of the value is equal to or greater than the set value, and a configuration that inputs to the control unit through a low-pass filter that removes high-frequency components It can be implemented in the form.
[0043]
(3) In the above-described embodiment, as the configuration for obtaining the compression top dead center (TDC) as a reference for detecting the opening timing of the exhaust valve in the test target engine, the engine is operated in each of the normal rotation direction and the reverse rotation direction. The configuration in which the control unit obtains the compression top dead center by calculation based on the detection value of the pressure sensor that detects the pressure in the cylinder and the detection information of the encoder as the rotation phase detection means when rotating is illustrated. The present invention is not limited to such a configuration, and may be a configuration for detecting the compression top dead center from information on the rotational phase of the camshaft, control information for the fuel injection nozzle, and the like, and may be implemented in various forms.
[0044]
(4) In the said embodiment, although the diesel engine was illustrated as a test object engine, not only a diesel engine but a gasoline engine may be sufficient.
[0045]
(5) In the above embodiment, the test is performed in a state where the test target engine is transported to a predetermined test setting position by the transport device and fixed in position, but instead of such a configuration, for example, transport You may apply to the engine test apparatus which tests an engine, moving in the state synchronized with the conveyance conveyor with respect to the engine to be conveyed in the state in which the engine to be tested is conveyed by the conveyor etc. Further, the connection work between the crankshaft and the external drive means, the connection work of various sensors, and the like may be automatically performed using an automatic connection device instead of the manual work.
[0046]
(6) In the above embodiment, the pressure detection means is configured to be connected to the intake manifold, which is a detection target, via the buffer portion for pressure reduction. Not limited to this, the pressure may be detected by directly connecting to the intake port of the intake manifold.
[0047]
(7) In the above embodiment, the external drive means rotates the crankshaft by rotating the electric motor, but various drive means such as a hydraulic motor can be applied.
[0048]
(8) In the above embodiment, a four-cylinder engine is exemplified as the test target engine. However, the number of cylinders of the engine to be tested can be appropriately changed, and the engine to be tested The number of intake valves and exhaust valves can be changed as appropriate, and various engines can be applied as test target engines.
[0049]
(9) In the above embodiment, the example in which the intake valve opening timing detection device in the test target engine according to the present invention is applied to the engine test device has been described. It can also be a device, and can be applied to various devices related to engine tests.
[Brief description of the drawings]
FIG. 1 is a schematic diagram of an engine test apparatus. FIG. 2 is a schematic diagram of an engine to be tested. FIG. 3 is a diagram showing a connection state of a pressure sensor. FIG. 4 is a flowchart of a control operation. 6] Flow chart of control operation [FIG. 7] Timing chart in compression top dead center detection [FIG. 8] Graph showing the relationship between engine operating state and pressure fluctuation [FIG. 9] Partial enlarged view of FIG. ]
1 Test target engine 3 External drive means 4 Crankshaft 5 Rotation phase detection means 9 Intake valve 10 Exhaust valve 17 Intake manifold 21 Pressure detection means 101 Timing detection means

Claims (3)

A plurality of cylinders are assembled such that an intake valve and an exhaust valve are opened and closed as the crankshaft rotates, and connected to the crankshaft in the engine under test in which the intake manifold is assembled. External drive means for forcibly rotating
Rotational phase detection means for detecting the rotational phase of the crankshaft;
Pressure detecting means for detecting the internal pressure of the intake manifold;
Based on the detection information of the pressure detection means and the detection information of the rotation phase detection means in a state where the crankshaft is rotated by the external drive means with the intake portion of the intake manifold closed. And an intake valve opening timing detection in a test target engine configured to detect, as a timing for opening the intake valve, a rotation phase at which the internal pressure of the intake manifold changes from a decreasing tendency to an increasing tendency. apparatus. The timing detection means;
Ascending state determination processing for determining whether or not the amount of change per unit time after the internal pressure of the intake manifold has changed from a decreasing tendency to an increasing tendency has become a set value;
When it is determined that the amount of change per unit time of the internal pressure has reached the set value in the rising state determination process, the amount of change from the rotation phase when the amount of change has reached the set value is the upper side in the rotational direction. 2. The intake valve opening timing detection device for a test target engine according to claim 1, wherein a phase calculation process for obtaining the rotation phase of the engine as a rotation phase that changes from a decreasing tendency to an increasing tendency is performed. The timing detection means;
The pressure detection value detected by the pressure detection means is sampled at each set cycle, and a moving average value for each set number of the sampled sampling values is obtained, and the moving average value changes from a decreasing tendency to an increasing tendency. 3. The intake valve opening timing detection apparatus for an engine under test according to claim 1, wherein the rotation phase is detected as an opening timing of the intake valve.

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