JP4244832B2 - Engine block vibration transfer characteristic analyzer - Google Patents

Description

The present invention relates to a vibration transfer characteristic analyzing device for an engine block and a vibration device employed in the device.

  One of the engine controls for obtaining a comfortable ride when a vehicle equipped with an engine that is an internal combustion engine is running is a method for detecting the occurrence of knocking in the engine and controlling the engine so as to eliminate knocking. There is. In order to realize this control, a knocking sensor is provided in the engine, vibration generated when knocking occurs is detected by the knocking sensor, and combustion conditions of the engine are set based on this detection information.

  When knocking occurs, it is necessary to accurately detect knocking vibration generated in the engine block by a knocking sensor. Specifically, it is important to know in advance the transmission characteristics of knocking vibration generated in the engine block when knocking occurs (hereinafter referred to as knocking vibration transmission characteristics). Therefore, it is conceivable to experimentally give a vibration to the engine block to generate a knocking vibration in a pseudo manner in the engine block and to grasp the knocking vibration transmission characteristic in advance. However, at the present stage, there is no engine block vibration transfer characteristic analyzer for measuring and analyzing knocking vibration in advance.

  In Patent Document 1 below, a combustion chamber of an engine filled with a liquid is vibrated using both a hydraulic vibration actuator and a piezoelectric vibration actuator in accordance with a control signal stored in advance, and the actual engine engine is simulated. A pseudo combustion vibration apparatus that reproduces the in-cylinder pressure is disclosed. When this apparatus is used, as shown in FIG. 20, it is possible to know in advance the vibration noise characteristics (vibration transfer characteristics in a specific frequency range) of the engine block due to the combustion pressure. However, it is impossible to obtain the knocking vibration transmission characteristic itself in the actual engine.

In addition, in order to obtain the vibration transmission characteristics, it is necessary to accurately vibrate the vibration to be vibrated while maintaining a predetermined angle (for example, in the vertical direction). Patent Document 2 listed below discloses an invention related to a coupling structure of vibration shafts, but does not disclose a vibration device for obtaining vibration characteristics in a specific engine.
JP 11-094690 A Japanese Patent Laid-Open No. 08-136392

  Accordingly, a first object of the present invention is to provide an engine block vibration transfer characteristic analyzing apparatus and a vibration transfer characteristic analyzing method using the apparatus for obtaining knocking vibration characteristics and the like in an engine. A second object of the present invention is to provide a vibration apparatus for accurately vibrating vibrations while maintaining a predetermined angle with respect to an object to be vibrated.

  The engine block vibration transfer characteristic analyzing apparatus according to the present invention is used to vibrate an engine block including a cylinder head and a cylinder block having a cylinder bore and analyze the vibration transfer characteristic of the engine block. An engine block vibration transfer characteristic analyzing apparatus, comprising: a cylinder block vibration measuring device disposed in an area corresponding to a combustion chamber on an inner surface of the cylinder bore; and an inner surface of the cylinder head facing the combustion chamber. A cylinder head vibration measuring device and a vibration device connected to a predetermined position of the engine block and for applying a predetermined vibration to the engine block are provided.

  In another aspect of the engine block vibration transfer characteristic analyzing apparatus, the cylinder block has a knock sensor mounting boss for mounting a knocking sensor for detecting the occurrence of knocking, and the vibration exciter includes the knocking sensor. They are connected using a sensor mounting boss.

  In another aspect of the engine block vibration transfer characteristic analyzing apparatus, the cylinder head has a plug hole for fixing the plug, and the cylinder head vibration measuring instrument is arranged using the plug hole. .

  An engine block vibration transfer characteristic analysis apparatus according to another embodiment is a method for analyzing vibration transmission characteristics of an engine block using the above-described engine block vibration transfer characteristic analysis apparatus, and includes the following steps: ing.

  First, a step of applying a predetermined vibration to the engine block by a vibration device connected to a predetermined position of the engine block, and a vibration of a region corresponding to a combustion chamber on the inner surface of the cylinder bore based on the vibration of the engine block Measuring with the cylinder block vibration measuring device, measuring the vibration of the cylinder head facing the combustion chamber based on the vibration of the engine block with the cylinder head vibration measuring device, and the cylinder block vibration measuring device. Analyzing vibration transmission characteristics of the cylinder block based on vibration information obtained from the above and vibration information obtained from the cylinder head vibration measuring instrument.

  In addition, the vibration device according to the present invention has a vibration shaft provided so as to connect the vibration object and the vibration device, and the vibration object is excited using the vibration device. A vibration device for vibrating, wherein the vibration shaft receives the vibration rod coupled to the object to be vibrated and the vibration rod so as to be slidable. A bottomed shaft hole extending to the other end, and an attachment to which the vibration exciter is connected to the other end, and a fixing means for fixing the vibration rod to the attachment.

  Further, in the vibration device in another form, the vibration shaft accommodates the vibration rod to the maximum extent in the shaft hole, and the vibration rod is inclined to the maximum with respect to the shaft hole. The angle formed by the inner wall surface of the shaft hole and the generatrix of the outer peripheral surface of the vibration rod in contact with the inner wall surface is the guaranteed angle, and the excitation angle is set so that the guaranteed angle is not more than a predetermined angle. The relationship between the rod and the shaft hole of the attachment is defined.

  According to the vibration transmission characteristic analysis apparatus for an engine block and the vibration transmission characteristic analysis method using the apparatus based on the present invention, a predetermined vibration is applied to the engine block by the vibration exciter, and the vibration transmission is measured by the cylinder block vibration. It can be measured by a measuring device and a cylinder head vibration measuring device.

  Here, since the piston position at the time of occurrence of knocking in the engine is in the range of about 10 ° to 60 ° after compression top dead center (ATDC), vibration transmitted to the cylinder block in the combustion chamber is suppressed by the piston, Vibration transmission from the cylinder head (head lateral vibration) becomes dominant. On the other hand, when the piston position is lowered, the suppression of the cylinder block by the piston is released, and the cylinder block starts to resonate. This cylinder block resonance affects engine noise at the ignition timing of knocking, and affects the SN (knocking signal / noise signal) ratio in the knocking sensor.

  Accordingly, in the present invention, by providing two types of vibration measuring devices, a cylinder block vibration measuring device and a cylinder head vibration measuring device, a response signal when a predetermined vibration is applied to the engine block by the vibration exciting device. Is picked up by the cylinder block vibration measuring device and the cylinder head vibration measuring device, so that the vibration characteristics of the cylinder block and the vibration characteristics of the cylinder head can be grasped. As a result, it is possible to obtain an S / N ratio based on a knocking signal (S: vibration characteristic of the cylinder head) and a noise signal (N: vibration characteristic of the engine block) as vibration transmission characteristics of the engine block.

  In addition, in the actual engine, knocking vibration is generated by connecting the vibration device to the cylinder block using the knock sensor mounting boss and arranging the cylinder head vibration measuring device using the plug hole. Vibration generated in the chamber is transmitted to the cylinder head and cylinder block and picked up as a vibration signal by the knock sensor attached to the knock sensor mounting boss, but the vibration signal is transmitted through a path opposite to this transmission path. This makes it possible to accurately pick up the transmitted vibration signal using the cylinder block vibration measuring device and the cylinder head vibration measuring device.

  Further, by utilizing the knock sensor mounting boss and the plug hole already provided in the engine block, it is possible to avoid additional processing on the engine block for mounting the vibration device and the cylinder head vibration measuring instrument. In addition, the knock sensor mounting boss and plug hole are provided with high positional accuracy with respect to the engine block, so that vibration is applied by the vibration exciter and vibration pickup by the cylinder head vibration measuring instrument. It can be performed with high accuracy.

  Moreover, according to the vibration device based on this invention, in the vibration shaft provided so that a to-be-vibrated object and a vibration device may be connected, the connection mechanism of a vibration rod and an attachment to this vibration shaft Is adopted. Thereby, it becomes possible to improve the ease of the connection operation | work to a to-be-excited object, and the precision of the connection positioning to a to-be-excited object. In addition, by defining the gap between the shaft hole and the vibration rod so that the guaranteed angle generated when the vibration rod is inserted into the shaft hole of the attachment is less than a certain angle, Thus, it is possible to accurately vibrate in a predetermined angular direction.

(Embodiment 1)
Embodiments of a vibration transfer characteristic analyzing apparatus for an engine block and a vibration transfer characteristic analyzing method using the apparatus based on the present invention will be described below with reference to the drawings.

  First, an engine block vibration transfer characteristic analyzing apparatus and a vibration transfer characteristic analyzing method using the apparatus according to the first embodiment will be described with reference to FIGS. FIG. 1 is an overall perspective view showing a configuration of an engine block vibration transfer characteristic analyzing apparatus 100 and a computer 200 according to the present embodiment, and FIG. 2 is a side view showing a structure of the engine block vibration transfer characteristic analyzing apparatus 100. FIG. 3 is a schematic view showing the structure of the high-precision height adjusting mechanism 120, and FIG. 4 is a schematic cross-sectional view showing the internal configuration of the engine block. 5 is an enlarged cross-sectional view of the cylinder head 162, and FIG. 6 is a view taken along line VI in FIG.

(Structure of vibration transfer characteristic analyzer 100)
As shown in FIGS. 1 and 2, the structure of the vibration transfer characteristic analyzing apparatus 100 in the present embodiment has an engine block 160 on which a vibration transfer characteristic is to be analyzed on a surface plate 110, and a predetermined value for the engine block 160. And a vibration exciter 130 for applying the above vibration. An anti-vibration rubber 150 is interposed between the engine block 160 and the surface plate 110 in order to block vibration from the outside. In addition, the high-accuracy height adjustment mechanism 120 is interposed between the vibration device 130 and the surface plate 110 from the viewpoint of accurately applying vibration to the engine block 160. As the vibration device 130, an electromagnetic vibration device or the like is used. Note that the external dimensions of the vibration transfer characteristic analyzing apparatus 100 in the present embodiment are about 450 mm wide, 450 mm deep, and 400 mm high.

  As shown in FIG. 2, the vibration device 130 has a support bolt 131 of the vibration device 130 in a U-shaped groove 123 provided in a holding jig 122 attached to the base 121 of the high-precision height adjustment mechanism 120. It is held and allows for a rough height adjustment. Further, as shown in FIG. 3, the high-precision height adjusting mechanism 120 includes a wedge member 121b and a wedge member 121c disposed in the case 121a of the base 121, and by rotating the handle 121d, The wedge member 121c moves in the X direction and the Y direction, and the height position can be adjusted in units of several tens of micrometers.

  As shown in FIG. 2, the engine block 160 includes a cylinder block 161 having a cylinder bore and a cylinder head 162, and the vibration shaft 140 of the vibration device 130 is attached to a knock sensor mounting boss 163 provided on the cylinder block 161. It is connected. The detailed configuration of the excitation shaft 140 will be described later. The knock sensor mounting boss 163 is a cylindrical protrusion for mounting a knock sensor that detects the occurrence of knocking in an actual engine.

  Referring to FIG. 4, a cylinder block vibration detection sensor 310 as a cylinder block vibration measuring instrument is disposed at a position of the cylinder block 161 facing the knock sensor mounting boss 163 on the inner surface of the cylinder bore 161A. In an actual engine, a piston 164 that slides up and down is disposed in the cylinder bore 161A, and the position where the cylinder block vibration detection sensor 310 is disposed is disposed in a region corresponding to the combustion chamber A on the inner surface of the cylinder bore. Is done. Since the knock sensor mounting boss 163 is formed with high accuracy, the vibration shaft 140 can be mounted with high accuracy on the cylinder block 161.

  Referring to FIG. 5, a cylinder head vibration detection sensor 320 as a cylinder head vibration measuring device is disposed in a plug hole 162p provided in the cylinder head 162. The cylinder head vibration detection sensor 320 includes special bolts 301, It consists of a metal cube 302 and a sensor 303. A more specific configuration will be described later. As shown in FIG. 6, the plug hole 162p is provided in the central region of the cylinder head 162 surrounded by the intake valve hole 162i and the exhaust valve hole 162e provided in the cylinder head 162. Further, since the plug hole 162p is formed with high accuracy by machining, the cylinder head vibration detection sensor 320 can be attached to the cylinder head 162 with high accuracy.

(Knock vibration analysis method)
A vibration analysis method of the engine block 160 when knocking occurs, using the vibration transfer characteristic analysis apparatus 100 having the above-described configuration, specifically, a knocking signal (S: vibration characteristic of the cylinder head) is used as the vibration transfer characteristic of the engine block 160. ) And a noise signal (N: vibration characteristic of the engine block), a method for obtaining the SN ratio will be described. First, a predetermined vibration is applied to the engine block 160 from the vibration shaft 140 connected to the knock sensor mounting boss 163 of the engine block 160 using the vibration device 130.

  Next, the vibration signal 1 generated in the cylinder block 161 and the vibration signal 2 generated in the cylinder head 162 are picked up using the cylinder block vibration detection sensor 310 and the cylinder head vibration detection sensor 320. The vibration signal 1 and the vibration signal 2 are input to the computer 200, and vibration transmission characteristics (S / N ratio) when the engine block 160 is knocked are analyzed.

(Specific analysis method for vibration transfer characteristics)
Here, a specific analysis method of vibration transfer characteristics using the cylinder block vibration detection sensor 310 and the cylinder head vibration detection sensor 320 will be described with reference to FIGS. 7 is a schematic diagram illustrating the vibration generated in the cylinder block 161 and the vibration generated in the cylinder head 162, and FIG. 8 is a diagram illustrating the relationship between the signal intensity at the knocking ignition timing and the knocking occurrence frequency. .

  As shown in FIG. 7, the position of the piston 164 at the time of occurrence of knocking in the actual engine is within a range of about 10 ° to 60 ° after compression top dead center (ATDC), so that it is transmitted to the cylinder block 161 in the combustion chamber A. The vibration to be suppressed is suppressed by the piston 164, and vibration transmission from the cylinder head 162 (S: head portion vibration response) becomes dominant. On the other hand, when the position of the piston 164 is lowered, the suppression of the cylinder block 161 by the piston 164 is released, and the cylinder block 161 starts to resonate (N: liner portion vibration response).

  The resonance of the cylinder block 161 affects engine noise at the ignition timing of knocking and increases the noise signal. As a result, the SN (knocking signal / noise signal: head portion vibration response S / liner portion vibration response N) in the knocking sensor is increased. ) Will adversely affect the ratio. That is, as shown in FIG. 8, the noise signal N shifts to the noise signal N ′ (intensity increases), and as a result the noise signal approaches the knocking determination level (S), the SN ratio is deteriorated. Become. In this manner, the lateral vibration (initial vibration) of the engine block 160 at the ignition timing of occurrence of knocking is dominated by vibration transmission from the cylinder head 162, and the signal from the cylinder block 161 becomes a noise signal.

  Therefore, in the vibration transfer characteristic analyzing apparatus 100 according to the present embodiment, two types of vibration measurement sensors, the cylinder block vibration measurement sensor 310 and the cylinder head vibration measurement sensor 320, are disposed in the combustion chamber A, thereby adding pressure. A response signal when a predetermined vibration is applied to the engine block 160 by the vibration device 130 is picked up by the cylinder block vibration measurement sensor 310 and the cylinder head vibration measurement sensor 320, whereby the vibration characteristics of the cylinder block 161 and the vibration of the cylinder head 162 are picked up. It is possible to grasp in advance the characteristics, that is, the SN ratio based on the knocking signal (S: vibration characteristic of the cylinder head) and the noise signal (N: vibration characteristic of the engine block).

(Correlation between the SN ratio obtained by the vibration transfer characteristic analyzer 100 and the SN ratio of the actual engine)
Here, the correlation between the SN ratio obtained by the vibration transfer characteristic analyzing apparatus 100 and the SN ratio of the actual engine will be described with reference to FIGS. FIG. 9 is a diagram showing the relationship between the various engines obtained by the vibration transfer characteristic analyzing apparatus 100 and the pseudo S / N ratio, and FIG. 10 is a diagram of various engines in a state where the engine is actually driven. It is a figure which shows a real machine SN ratio pass / fail.

  The SN ratio at the time of occurrence of engine knocking obtained by the vibration transfer characteristic analyzer 100 is defined as a pseudo SN ratio, and the SN vibration ratio obtained from actual engine driving is defined as an actual SN ratio. From the engine (A), the engine (B), and the engine (C), the pseudo SN ratio and the actual machine SN ratio were compared.

  As a result of measuring the pseudo S / N ratio of each engine using the engine blocks of the engine (A), the engine (B), and the engine (C) using the vibration transfer characteristic analyzing apparatus 100, FIG. 9 shows. Thus, the pseudo S / N ratio with the best controllability of the engine (A) was obtained, and then the pseudo S / N ratio was obtained in the order of the engine (C) and the engine (B).

  Next, the engine (A), engine (B), and engine (C) are actually driven, signals are picked up by knock sensors, and the actual SN ratio is measured. Show. In the engine (A) and the engine (C), an acceptable SN ratio was obtained, and in the engine (B), an unacceptable SN ratio was obtained. Thus, in the engine (B) with the worst pseudo S / N ratio, the actual machine S / N ratio is also judged to be unacceptable, and there is a correlation between the S / N ratio obtained by the vibration transfer characteristic analyzer 100 and the S / N ratio of the actual machine engine. Proven to have a relationship.

(Specific Configuration of Cylinder Head Vibration Detection Sensor 320)
Next, a specific configuration of the cylinder head vibration detection sensor 320 will be described with reference to FIG. Here, as described above, in the cylinder head vibration detection sensor 320, it is necessary to accurately measure the transverse vibration component generated in the cylinder head 162, and therefore, it is necessary to pay sufficient attention to its mounting position and angle. For example, if the mounting angle with respect to the cylinder head 162 is inaccurate, a measurement error occurs due to a difference in the vibration vector direction. Therefore, in the present embodiment, the cylinder head vibration detection sensor 320 is attached using the plug hole 162p provided in the cylinder head 162.

  As described above, the cylinder head vibration detection sensor 320 includes the special bolt 301, the metal cube 302, and the sensor 303. Here, when the sensor 303 is attached to the special bolt 301, the accuracy of the attachment angle is required. Therefore, a metal cube 302 (cubic shape) finished with high dimensional accuracy by machining is used as the special bolt 301. Between the sensor 303 and the sensor 303. The special bolt 301 and the metal cube 302 are preferably made of the same material as the cylinder head 162 from the viewpoint of preventing measurement errors.

  Various fixing structures are conceivable for fixing the metal cube 302 to the special bolt 301. 11A is a fixing structure using an adhesive, and FIG. 11B is a fixing structure in which a male screw 305A is provided on the special bolt 301 side, and a female screw 305B is received on the metal cube 302 side. 11 (C), a fixing structure provided with a male screw 305A on the metal cube 302 side and a female screw 305B for receiving the male screw 305A on the special bolt 301 side, an independent male screw (stud bolt) shown in FIG. 11 (D) For example, a fixing structure in which 305A is prepared and a female screw 305B for receiving the male screw 305A is provided on each of the special bolt 301 and the metal cube 302, and the like.

  In addition, since the accuracy of the mounting angle of the sensor 303 is required, the case where the metal cube 302 having a flat surface is provided has been described. However, this mounting structure is merely an example, for example, with respect to the cylinder head 162 When it is possible to satisfy the accuracy of the mounting angle, it is possible to adopt a fixing structure in which the sensor 303 is directly mounted on the cylinder head 162.

(Other configurations of excitation position)
In the vibration transfer characteristic analyzing apparatus 100, the vibration direction is accurately perpendicular to the cylinder block 161 (specifically, the inner wall surface of the cylinder bore 161A). In order to eliminate the need for additional processing to the cylinder block 161, the vibration shaft 140 of the vibration device 130 is coupled to the boss 163 using an existing knock sensor mounting boss 163. However, if it is not a problem to secure a high positional accuracy with respect to the cylinder block 161 and provide a mounting area, a separate area for connecting the excitation shaft 140 to the cylinder block 161 or the cylinder head 162 is provided. It is also possible.

  As another configuration for exciting the engine block 160, there is a method of exciting the cylinder head 162 as shown in FIG. In this vibration method, a vibration bolt 141 for vibration is screwed into a plug hole 162p provided in the cylinder head 162, and the vibration portion of the vibration device is connected to the vibration bolt 141. Let As shown in FIG. 12, not only the method of applying vibration (arrow F1) from the outside as shown in FIG. 12, but also the vibration bolt 141 is vibrated from the inside (combustion chamber side) as shown in FIG. A method of (arrow F2) is also conceivable. In addition to the case where the plug hole 162p is used, a dedicated bolt fixing hole can be separately formed.

  Further, as another configuration for exciting the engine block 160, as shown in FIG. 14, a screw hole 161h is formed on the side of the cylinder block 161 opposite to the excitation point P1. It is also possible to vibrate the engine block 160 (in the direction of arrow F3) by making the tip of the vibration bolt 141 abut the vibration point P1 using the hole 161h.

  Further, as another configuration for vibrating the engine block 160, as shown in FIG. 15, screw holes 161h are formed on opposite sides of the cylinder block 161, and the screw holes 161h are used. A method is also conceivable in which the vibration bolts 141 are screwed into the screw holes 161h and the vibration bolts 141 are vibrated (arrows F4 and F5).

(Action / Effect)
As described above, according to the vibration transmission characteristic analysis apparatus 100 for engine blocks and the vibration transmission characteristic analysis method using this apparatus according to the present embodiment, the two types of vibrations of the cylinder block vibration measurement sensor 310 and the cylinder head vibration measurement sensor 320 are used. By arranging a measurement sensor in the firing chamber and picking up a response signal when a predetermined vibration is applied to the engine block 160 by the vibration device 130 by the cylinder block vibration measurement sensor 310 and the cylinder head vibration measurement sensor 320, The vibration characteristics of the cylinder block 161 and the vibration characteristics of the cylinder head 162 can be grasped. As a result, the S / N ratio based on the knocking signal (S: vibration characteristic of the cylinder head) and the noise signal (N: vibration characteristic of the engine block) can be obtained as the vibration transmission characteristic of the engine block 160.
(Embodiment 2)
Hereinafter, as a second embodiment, a structure of a vibration exciter used in a vibration transfer characteristic analyzer for an engine block according to the present invention will be described with reference to the drawings. As described in the first embodiment, in the vibration transfer characteristic analysis device 100 for the engine block, the excitation direction is perpendicular to the cylinder block 161 in order to accurately measure the S / N ratio. It is necessary to vibrate accurately. Therefore, as an example, the vibration shaft 140 of the vibration device 130 is connected to the existing knock sensor mounting boss 163. However, in the case where the vibration shaft 140 itself has a problem that the vibration direction is shifted, an accurate measurement result cannot be obtained even when the vibration shaft 140 is mounted on the knock sensor mounting boss 163. . Therefore, the excitation shaft 140 shown below has a structure that does not cause such a problem.

  Hereinafter, a specific configuration of the vibration shaft 140 employed in the vibration device 130 will be described with reference to FIG. As shown in FIG. 16, the vibration shaft 140 includes a vibration rod 145 and an attachment 146. The attachment 146 is provided with a bottomed shaft hole 146h that is open at one end and extends to the other end in order to slidably receive the vibration rod 145. The other end is connected to the vibration device 130. Yes. Further, a screw hole 146s intersecting the shaft hole 146h and a fixing screw 146b screwed into the screw hole 146s are provided on the side surface of the attachment 146 in order to position and fix the vibration rod 145. In the present embodiment, a round bar is used for the excitation rod 145, and a cylindrical shaft hole capable of accommodating the round bar is formed in the shaft hole 146h. However, the shape is particularly limited to this shape. It is not something.

  One end of the excitation rod 145 is connected to the engine block 160 that is the object to be excited, and the other end side of the excitation rod 145 is accommodated in the shaft hole 146h of the attachment 146, and the accommodation distance is adjusted. The distance between the engine block 160 and the vibration exciter 130 is adjustable. When the adjustment of the distance between the two ends, the fixing screw 146 b is tightened, and the vibration rod 145 is fixed to the attachment 146.

  The vibration rod 145 is fixed in a state where it is accommodated in the shaft hole 146h. However, when the shaft center of the vibration rod 145 and the shaft center of the shaft hole 146h are shifted and fixed, the vibration from the vibration device 130 is fixed. The vibration force and the direction of vibration are not accurately transmitted to the vibration rod 145. FIG. 17 shows the vector direction of the excitation force when the axis of the excitation rod 145 directly connected to the engine block 160 is shifted by θ with respect to the excitation direction. When the excitation direction is not shifted, no component force of the excitation force is generated in the Y direction. However, by shifting θ, a component force FY of the exciting force is generated in the Y direction. When such a component force FY is generated, an unnecessary excitation force is applied to the engine block 160 that is an object to be excited. As a result, as shown in FIG. 18, a “resonance peak deviation” and a “resonance frequency deviation” are generated with respect to the original transfer characteristics. As a result, in the vibration transfer characteristic analyzing apparatus 100 for the engine block, the S / N ratio cannot be measured accurately, and the reliability of the vibration transfer characteristic analyzing apparatus 100 is lowered.

  Therefore, in order to eliminate the occurrence of such a problem, as shown in FIG. 19, in the excitation shaft 140 in the present embodiment, as shown in FIG. 19, a shaft hole 146h of the attachment 146 of the excitation rod 145 is provided. The angle (θ) generated in the vibration rod 145 that is generated when the vibration rod 145 is inserted into the shaft hole 146h during the accommodation is determined as a guaranteed angle, and the vibration is performed so that this angle is equal to or less than a certain angle. The relationship between the rod 145 and the shaft hole 146h of the attachment 146 is defined.

  As an example, as shown in FIG. 19, the shaft hole in the state in which the excitation rod 145 is accommodated in the shaft hole 146h to the maximum and the excitation rod 145 is inclined to the maximum with respect to the shaft hole 146h. The angle formed by the inner wall surface S1 of 146h and the generatrix S2 of the outer wall surface of the vibration rod 145 in contact with the inner wall surface S1 is taken as a guaranteed angle (θ), and this guaranteed angle is about 0.382 ° or less. It is set as follows. By defining the relationship between the vibration rod 145 and the shaft hole 146h of the attachment 146 so as to be less than this angle, the vibration rod 145 can be vibrated in the vertical direction with respect to the engine block 160.

Specific dimensions for setting the guaranteed angle to about 0.382 ° or less include a distance L1 from the opening of the shaft hole 146h to the intersection of the bus bar S2 of the excitation rod 145 and the inner wall surface S1 of the shaft hole 146h. Is 30 mm, and the distance L2 from the generating line S2 to the inner wall surface S1 of the vibrating rod 145 at the opening of the shaft hole 146h is 200 μm, tan ⁻¹ (0.2 / 30) = 0.382 °. Note that the guaranteed angle is not limited to this value, and is appropriately determined depending on the vibration frequency to be measured (for example, 20 kHz).

(Action / Effect)
As described above, according to the vibration shaft 140 of the vibration device 130 according to the present embodiment, the connection mechanism between the vibration rod 145 and the attachment 146 is employed, thereby facilitating the connection work to the engine block 160, It becomes possible to maintain the accuracy of connection positioning to the engine block 160. Further, a gap between the shaft hole 146h and the vibration rod 145 is adopted so that the guaranteed angle (θ) generated when the vibration rod 145 is inserted into the shaft hole 146h, which is employed in the vibration shaft 140, is equal to or less than a certain angle. By defining, it is possible to accurately vibrate the vibration rod 145 with respect to the engine block 160 in the vertical direction.

  In the above embodiment, the vibration mechanism used in the engine block vibration transmission characteristic analyzer shown in the first embodiment has been described. However, the vibration mechanism is not limited to this and requires vibration. It can be widely applied to all devices.

  Accordingly, the above-described embodiment disclosed herein is illustrative in all respects and does not serve as a basis for limited interpretation. Therefore, the technical scope of the present invention is not interpreted only by the above-described embodiments, but is defined based on the description of the claims. Further, all modifications within the meaning and scope equivalent to the scope of the claims are included.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an overall perspective view showing a configuration of a vibration transfer characteristic analyzing apparatus for an engine block and a computer in Embodiment 1 based on the present invention. It is a side view which shows the structure of the vibration transmission characteristic analysis apparatus of the engine block in Embodiment 1 based on this invention. It is a schematic diagram which shows the structure of the high precision height adjustment mechanism in Embodiment 1 based on this invention. It is a schematic cross section which shows the internal structure of the engine block in Embodiment 1 based on this invention. It is an expanded sectional view of the cylinder head in Embodiment 1 based on this invention. FIG. 6 is a view taken along line VI in FIG. 5. It is the schematic diagram which illustrated the vibration which arises in a cylinder block, and the vibration which arises in a cylinder head. It is a figure which shows the relationship between the signal intensity | strength in knocking generation | occurrence | production ignition timing, and knocking generation frequency. It is a figure which shows the relationship between the various engines and pseudo | simulation S / N ratio which were obtained by the vibration transfer characteristic analyzer in Embodiment 1 based on this invention. It is a figure which shows the actual machine SN ratio acceptance in various engines in the state which actually driven the engine in Embodiment 1 based on this invention. (A)-(D) is a figure which shows the specific structure of the cylinder head vibration detection sensor in Embodiment 1 based on this invention. It is a figure which shows the structure for vibrating an engine block in the other form of Embodiment 1 based on this invention. It is a figure which shows the structure for vibrating an engine block in the further another form of Embodiment 1 based on this invention. It is a figure which shows the structure for vibrating an engine block in the further another form of Embodiment 1 based on this invention. It is a figure which shows the structure for vibrating an engine block in the further another form of Embodiment 1 based on this invention. It is a figure which shows the specific structure of the vibration axis | shaft of the vibration apparatus in Embodiment 2 based on this invention. It is a figure which shows the case where the axial center of the vibration rod directly connected with an engine block has shifted | deviated (theta) with respect to the vibration direction. It is a figure which shows the relationship between a frequency and a transfer characteristic in case "deviation of a resonance point peak" and "deviation of a resonance frequency" generate | occur | produce. It is a figure for demonstrating the guarantee angle ((theta)) of the vibration axis of the vibration apparatus in Embodiment 2 based on this invention. It is a figure which shows the relationship between the frequency in a background technique, and a transfer characteristic.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 100 Vibration transfer characteristic analyzer, 110 Surface plate, 120 High precision height adjustment mechanism, 121 Base, 121a Case, 121b, 121c Wedge member, 121d Handle, 122 Holding jig, 123 U-shaped groove, 130 Excitation device, 131 Support bolt, 140 Exciting shaft, 141 Exciting bolt, 145 Exciting rod, 146 Attachment, 146h Shaft hole, 146s Screw hole, 146b Fixing screw, 150 Anti-vibration rubber, 161 Cylinder block, 161A Cylinder bore, 161h Screw hole, 160 Engine block, 162 Cylinder head, 162e Exhaust valve hole, 162i Intake valve hole, 162p Plug hole, 163 Knock sensor mounting boss, 164 Piston, 200 Computer, 301 Special bolt, 302 Metal cube, 303 Sa, 305A male thread, 305B female thread, 310 cylinder block vibration detection sensor, 320 a cylinder head vibration detection sensors, A combustion chamber, P1 vibration point, S1 inner wall surface, S2 bus.

Claims (5)

An engine used for analyzing a vibration transmission characteristic of the engine block (160) by exciting an engine block (160) including a cylinder block (161) having a cylinder head (162) and a cylinder bore (161A). An apparatus for analyzing vibration transmission characteristics of a block,
A cylinder block vibration measuring device (310) disposed in a region corresponding to the combustion chamber (A) on the inner surface of the cylinder bore (161A);
A cylinder head vibration measuring device (320) facing the combustion chamber (A) and disposed on the inner surface of the cylinder head (162) ;
A vibration transmission characteristic analysis device for an engine block, comprising: a vibration exciter (130) coupled to a predetermined position of the engine block (160) to apply a predetermined vibration to the engine block (160) . The cylinder block (161) has a knock sensor mounting boss (163) for detecting the occurrence of knocking,
The vibration transmission characteristic analysis apparatus for an engine block according to claim 1, wherein the vibration exciter (130) is connected using the knock sensor mounting boss (163). The cylinder head (162) has a plug hole (162p) for fixing the plug, and the cylinder head vibration measuring instrument (320) is arranged using the plug hole (162p). The vibration transmission characteristic analysis device for an engine block according to claim 1 or 2. The vibration exciter (130)
An excitation shaft (140) provided to connect the object to be excited and the excitation device (130), and for exciting the object to be excited using the excitation device A device,
The excitation shaft (140)
An excitation rod (145) connected to the object to be excited ;
In order to slidably receive the excitation rod (145), a bottomed shaft hole (146h) that is open at one end and extends to the other end is provided, and the excitation device (130) is connected to the other end. Attachment (146)
Fixing means (146b) for fixing the excitation rod (145) to the attachment (146);
An engine block vibration transfer characteristic analyzer according to any one of claims 1 to 3, further comprising: The excitation shaft (140) accommodates the excitation rod (145) in the shaft hole (146h) to the maximum, and the excitation rod (145) is inclined to the shaft hole (146h) to the maximum. In the state, the angle formed by the inner wall surface of the shaft hole (146h) and the generatrix of the outer peripheral surface of the excitation rod (145) in contact with the inner wall surface is a guaranteed angle,
The relationship between the excitation lock (145) and the shaft hole (146h) of the attachment (146) is defined so that the guaranteed angle is equal to or less than a predetermined angle. For analyzing vibration transmission characteristics of engine blocks.

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