JP4837846B2 - Pulley for belt load measurement - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for easily measuring a belt load without affecting the measurement system when measuring the belt load of a belt transmission device arranged in an overcrowded space. Relates to a pulley that measures the belt load without affecting the pulley layout of the actual engine when measuring the belt load of a belt drive for driving an auxiliary machine used in an automobile engine.
[0002]
[Prior art]
As is well known, the belt drive device for driving auxiliary equipment used in automobile engines increases the number of auxiliary equipment used in conjunction with the upgrading of automobiles, and it is necessary to reduce the weight and size of the vehicle body. The layout of deploying this auxiliary machine around the engine is overcrowded.
[0003]
As shown in FIG. 3, the auxiliary drive belt transmission device includes an air conditioner (A / C), an AC generator (ACG), a power steering (P / S), a water pump (W / P) around the engine crankshaft. ), An auxiliary machine such as an oil pump (O / P), etc., a belt is wound around the auxiliary pulley and the crank pulley, and each auxiliary machine is operated by driving the crank pulley.
[0004]
In addition, since this belt drive device for driving auxiliary equipment transmits the load to the auxiliary equipment through belt tension, the dynamic characteristics (power transmission performance, soundproofing performance, etc.) of the belt drive, or the durability of the belt In the evaluation, the belt tension is an indispensable condition.
[0005]
As a method for measuring the belt tension, first, if the static belt tension is measured when the engine is stopped, the required belt tension can be obtained by measuring the belt resonance frequency between the belt spans.
[0006]
Secondly, for dynamic belt tension measurement when the engine is running, a belt load measurement pulley with a built-in load measurement function (a sensor such as a strain gauge) is temporarily placed between the belt spans, or a new mounting base A method such as providing a stand and fixing it in earnest was used.
[0007]
However, in the first method, only the static belt tension can be measured, and the dynamic characteristics cannot be appropriately evaluated as described above. In the second method, the dynamic belt tension can be measured. However, in this method, an extra pulley is added to the existing pulley layout, so that the pulley layout is different from the actual machine. This detrimental effect had a particularly negative impact on the evaluation of dynamic properties involving inertia.
[0008]
[Problems to be solved by the invention]
Therefore, as a method for measuring the belt load without changing the actual pulley layout, a belt load measuring pulley 3 ′ shown in FIG. 6 has been used. The pulley 3 'for measuring the belt load has the same external dimensions (pulley outer diameter and width) as the actual pulley, and has a bearing 9 incorporated therein, and the bearing 9 is fitted to a predetermined mounting member 7. It is fixed or temporarily arranged on the mounting base base 8 as much as possible. At this time, the pulley 3 'for belt load measurement is replaced and assembled as a dummy of the actual idler pulley.
[0009]
As shown in the figure, the resultant tension of the belt tension by the belt 2 wound around the belt load measuring pulley 3 ′ becomes a belt load (external force) and acts on the pulley outer diameter portion of the belt load measuring pulley 3 ′. This belt load causes a stress strain due to a bending moment to occur in the cantilever mounting member 7 having the mounting base 8 as a fixed fulcrum.
[0010]
As shown in the figure, the attachment member 7 is formed with a thin portion in a direction intersecting with the belt load direction by 90 degrees, and thus has a structure that is easily bent in the belt load direction. It is affixed.
[0011]
Since the strain strain due to the bending moment is generated at the position where the strain gauge 10 is applied, the strain gauge 10 is connected to a Wheatstone bridge and a dynamic strain meter (not shown), the strain amount is measured, and the strain is converted into a belt load. Can finally measure the belt tension.
[0012]
However, the following problems remain in the above conventional method. That is, when the belt load measuring pulley 3 ′ shown in FIG. 6 is used in the pulley layout shown in FIG. 3, adjacent auxiliary machine components, engine covers, around the actual idler pulley 6 to be replaced. Alternatively, since the engine body and the like are arranged in an overcrowded state, it is practically difficult to assemble the pulley 3 'for measuring the belt load.
[0013]
That is, the pulley 3 ′ for measuring the belt load requires an extra space for attaching the strain gauge 10 to the mounting member 7 as shown in FIG. Space was limited.
[0014]
Therefore, as shown in FIG. 2, even if the actual idler pulley 6 is removed and the belt load measuring pulley 3 ′ is attached to the trace, the attachment member 7 of the belt load measuring pulley 3 ′ is attached to the mounting base base 8. It interfered and could not be physically installed.
[0015]
In addition, as shown in FIG. 6, there is a method of mounting by changing the direction of the mounting member 7 by 180 degrees. However, even with this method, the mounting base 8 must be constructed on the base 12 opposite to the engine body 11. In addition, the mounting base 8 is generally difficult to construct, and the mounting itself is unstable due to the overhang of the mounting member 7.
[0016]
Therefore, the present inventor has invented a pulley for measuring a belt load having a new structure in which the above-described drawbacks are improved.
[0017]
[Means for Solving the Problems]
That is, the invention of claim 1 is a pulley for detecting a belt load of a belt transmission device in which a belt is wound around a plurality of pulleys, and has a cylindrical belt suspension portion on the outer periphery and a cylindrical shape having a built-in bearing . An outer unit, a cylindrical inner unit that supports the outer unit on the inside and is fixed to the base table, a cylindrical outer extending member that extends to the side of the outer unit, and a side that extends to the side of the inner unit A cylindrical inner extending member, a connecting means for integrally connecting the outer extending member and the inner extending member, and a strain gauge attached to either the outer extending member or the inner extending member. This is a pulley for measuring the belt load.
[0018]
The invention according to claim 2 is the pulley for measuring a belt load according to claim 1, wherein a thin portion is formed on either the outer extending member or the inner extending member, and a strain gauge is attached to the thin portion. It is.
[0019]
The invention according to claim 3 is the pulley for belt load measurement according to claim 1 or 2, wherein the outer extending member or the inner extending member to which the strain gauge is attached is provided with a notch.
[0020]
The invention according to claim 4 is the belt load measuring pulley according to any one of claims 1 to 3, wherein the inner unit is detachably fitted and fixed to an attachment member protruding from the base.
[0021]
The invention according to claim 5 is the pulley for belt load measurement according to claims 1 to 4, wherein the connecting means is screwed to the flange portion formed at the end portion of the outer extending member and the inner extending member.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, it explains in detail using a drawing. FIG. 1 is a partial cross-sectional view showing a belt load measuring pulley according to an embodiment, and FIG. 2 is a partial cross-sectional view showing an idler pulley according to the present invention. FIG. 3 is a schematic diagram showing a pulley layout according to the present invention. FIG. 4 is a graph showing a time-series observation waveform according to the example, and FIG. 5 is a graph showing an RPM tracking analysis result of the belt tension according to the example. FIG. 6 is a partial cross-sectional view showing a belt load measuring pulley according to a conventional example.
[0023]
In FIG. 1, the belt load measuring pulley 3 according to the present invention is largely divided into an outer unit 5 having a built-in bearing 9 and an inner unit 4 that supports the outer unit 5 inward and fixes the outer unit 5 to the base base 8. The structure is divided.
[0024]
The outer unit 5 has a cylindrical portion that wraps a belt around the outer periphery and a cylindrical sleeve 5c that supports a bearing 9 on the inner periphery, and this sleeve 5c extends to one side to form a cylindrical outer contact member 5b. Form.
[0025]
The inner unit 4 includes a sleeve 4c that is fitted and positioned on a mounting member 7 protruding on the base base 8, and a cylindrical inner extending member 4b that extends from the sleeve 4c to one side. Form.
[0026]
The outer unit 5 and the inner unit 4 are integrated by connecting a cylindrical outer extending member 5b and a cylindrical inner extending member 4b. Specifically, the flange 5a and the flange 4a are formed at the ends of the outer extending member 5b and the inner extending member 4b, and these are connected.
[0027]
At this time, as shown in the figure, the flange 5a and the flange 4a are detachably coupled to each other by a bolt. A thin portion is formed in the intermediate portion of one of the connected outer extending member 5b and inner extending member 4b, and the strain gauge 10 is attached to that portion.
[0028]
Here, the thin portion formed in the intermediate portion of either the outer extending member 5b or the inner extending member 4b forms a thin ring as a whole, but such a ring structure is a structure that is difficult to deform. Therefore, there are drawbacks in that the gauge sensitivity is lowered and the linearity of the stress-strain diagram is distorted.
[0029]
Therefore, a gauge sensitivity is obtained by forming a thin portion in one of the outer extending member 5b and the inner extending member 4b and providing a notch portion in the cylindrical member located in the thin portion so as to have a substantially leaf spring structure. Is maintained properly.
[0030]
In this embodiment, since the strain gauge is affixed to the inwardly extending member 4b, the notch intersects the direction of the bending moment acting on the inwardly extending member 4b as shown in FIG. This is done by cutting out a predetermined width H in the direction.
[0031]
As a result, the inwardly extending member 4b is easily deformed in the direction of the bending moment indicated by the arrow in FIG. 3, and the strain gauge sensitivity can be increased. On the other hand, the provision of the notch has the advantage of widening the space and facilitating the strain gauge attaching operation.
[0032]
Since the base base 8 and the mounting member 7 use the original base base 8 provided in the engine body 11 of the actual engine as shown in FIG. 2, the actual idler shown in FIG. It is extremely easy to replace the pulley 6 with the belt load measuring pulley 3 of the embodiment shown in FIG.
[0033]
Next, the principle of measuring the belt load will be described in detail with reference to FIG. As shown in FIG. 1, the belt load due to the belt 2 acts on the belt load measuring pulley 3 in the direction of the arrow in the drawing. The external force due to the belt load is transmitted to the sleeve 5c via the bearing 9 of the outer unit 5, and further transmitted to the flange 5a via the outer extending member 5b. Since the flange 5a and the flange 4a of the inner unit 4 are detachably connected by bolts, the external force is further transmitted to the sleeve 4c via the inwardly extending member 4b. Since the sleeve 4c is fixed to the base base 8 of the engine main body 11 with bolts, the external force is counterbalanced by the base base 8 and balanced.
[0034]
The belt load can be measured at any part as long as it is within the force transmission path described above. However, in this embodiment, the outer extension member 5b is not provided with a thin portion in order to firmly support the bearing 9, A thin portion was formed on the inwardly extending member 4b, and a strain gauge 10 was attached to the thin portion.
[0035]
In addition, since both the outer extending member 5b of the outer unit 5 and the inner extending member 4b of the inner unit 4 have a structure that does not rotate, there is no need to provide a slip ring, and the strain gauge 10 attached to the inner extending member 4b. The belt load can be suitably measured by connecting the lead wire as it is to a Wheatstone bridge or dynamic strain meter (not shown).
[0036]
【Example】
Hereinafter, the pulley 3 for belt load measurement which concerns on an Example, and the experimental result performed using this are demonstrated in detail.
[0037]
The engine used in the experiment was an in-line 4-cylinder 1000 cc engine, and the belt transmission device to be measured was the belt transmission device for driving the engine accessory shown in FIG. The belt used in the experiment was a 4PK 1704 (4 ribs, 1704 mm circumference) V-ribbed belt manufactured by Mitsuboshi Belting.
[0038]
The outer dimensions of the belt load measuring pulley 3 were the same as those of the actual idler pulley 6, the pulley width was 25 mm, and the Pou outer diameter was 88 mm.
[0039]
In addition, a # 6008 ball bearing is used as the bearing 9, and the dimensions of the thin portion formed on the inner extending member 4c are 33 mm in outer diameter, 10 mm in width, and 1.0 mm in thickness. Affixed to a total of 4 strain gauges on both sides. The opening width H of the notch portion was 18 mm, four screw hole portions were provided in the flange 5a of the outer unit 5, and the flange 4a of the inner unit 4 was fixed in two layers with bolts.
[0040]
The pulley 3 for measuring the belt load assembled as described above was fixed to the attachment member 7 of the base base 8 of the actual engine through the sleeve 4c. As a result, the belt load measuring pulley 3 can be easily replaced with the belt load measuring pulley 3 without changing the pulley layout and without interfering with the actual engine.
[0041]
Hereinafter, a measurement example of a belt load that is suitably measured using the belt load measuring pulley 3 will be described with reference to FIGS. 4 and 5.
[0042]
The vertical axis of the graph in FIG. 4 indicates the belt tension (Kgf / 4 rib) in the steady operation state, and the horizontal axis indicates the time axis. The pulse waveform in the graph shows the rotation period of the crankshaft, and one pulse is synchronized with one rotation of the crankshaft.
[0043]
The graph of FIG. 5 shows the result of RPM tracking analysis of belt tension fluctuations using belt load data when the engine is accelerated / decelerated.
[0044]
As described above, by using the belt load measuring pulley 3 according to the present invention, the belt can be used under the same conditions as the actual machine without changing the outer dimensions of the actual machine idler pulley 6 and without affecting the pulley layout at all. It was possible to measure the load.
[0045]
Moreover, the belt load measuring pulley 3 according to the present invention can be easily separated from the inner unit 4 and the outer unit 5, and the inner extension member 4b is provided with a notch, so that the strain gauge 10 is attached. This has the effect of making the work and the pulley replacement work extremely easy and improving the gauge sensitivity of the strain gauge 10.
[0046]
The pulley 3 for measuring the belt load is not limited to the accessory driving belt device used for the automobile engine. In short, the belt load must be measured in the actual machine state in an overcrowded space where space is limited. It is suitably used for cases that must be handled.
[0047]
【The invention's effect】
Thus, the invention of claim 1 enables the belt load to be applied without affecting the pulley layout (that is, the measurement system) even if the belt drive device for driving the accessory has an overcrowded pulley layout represented by the engine. There is a remarkable effect that can be measured.
[0048]
The invention of claim 2 has an effect of facilitating the attaching operation of the strain gauge and improving the strain sensitivity of the strain gauge.
[0049]
The invention of claim 3 has an effect of improving the sensitivity of the strain gauge.
[0050]
Accordingly, the belt load measuring pulley can be easily replaced with the actual pulley.
[0051]
According to the fifth aspect of the present invention, the belt load measuring pulley can be easily assembled, the strain gauge can be easily applied, and the components can be modularized.
[Brief description of the drawings]
FIG. 1 is a partial cross-sectional view showing a belt load measuring pulley according to an embodiment.
FIG. 2 is a partial cross-sectional view showing an idler pulley according to the present invention.
FIG. 3 is a schematic view showing a pulley layout according to the present invention.
FIG. 4 is a graph showing time-series observation waveforms according to an example.
FIG. 5 is a graph showing an RPM tracking analysis result of belt tension according to an example.
FIG. 6 is a partial sectional view of a belt load measuring pulley according to a conventional example.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Belt transmission 2 Belt 3, 3 'Belt load measurement pulley 4 Inner unit 4a Flange 4b Inner extending member 4c Sleeve 5 Outer unit 5a Flange 5b Outer extending member 5c Sleeve 6 Idler-pulley 7 Mounting member 8 Base base 9 Bearing 10 Strain gauge 11 Engine body 12 Mounting base

Claims (5)

In a pulley for detecting the belt load of a belt transmission device in which a belt is wound around a plurality of pulleys, a cylindrical belt suspension portion is provided on the outer periphery, a cylindrical outer unit having a built-in bearing, and an outer unit on the inner side. A cylindrical inner unit that is supported and fixed to the base, a cylindrical outer extending member that extends to the side of the outer unit, and a cylindrical inner extending member that extends to the side of the inner unit And a connecting means for integrally connecting the outer extending member and the inner extending member, and a strain gauge affixed to either the outer extending member or the inner extending member. Pulley. 2. The pulley for measuring a belt load according to claim 1, wherein a thin portion is formed on one of the outer extending member and the inner extending member, and a strain gauge is attached to the thin portion. The pulley for belt load measurement according to claim 1 or 2, wherein a notch portion is provided in an outer extending member or an inner extending member to which a strain gauge is attached. 4. The belt load measuring pulley according to claim 1, wherein the inner unit is detachably fitted and fixed to an attachment member protruding from the base table. 5. The pulley for measuring a belt load according to claim 1, wherein the connecting means screws the flange portions formed at the end portions of the outer extending member and the inner extending member.

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